Close Call in Trench/Excavation Rescue

BY LARRY COLLINS

The following incident is an example of the occasional failure of measures and laws intended to protect workers in trenches and excavations (in this case, the failure of the employer to require adequate safety measures). It is also an example of the life-threatening conditions that confront firefighters responding to these emergencies and the proper measures that should be taken when these incidents occur. It is a case study in the ability of firefighters and rescue team members to be resourceful and effective when they have the right training, equipment, and experience and an example of the need to always consider the “risk vs. gain” equation before committing personnel to high-risk operations.

Before the incident was over, several firefighters experienced a “near-miss” from a large secondary collapse. Nearly a dozen units, including three USAR fire stations, one hazardous materials task force, and a host of first responders, responded. During the course of the day, unusual hazards compelled firefighters to purposely collapse an unstable wall onto the already-buried (and deceased) victim and to construct a variation on the flying raker inside the excavation.

This case study—and a review of the close call that occurred during the incident—is intended to reinforce the value of trench rescue training for first responders and of continuing education for all members to keep trench rescue lessons fresh in their minds. It is a reminder of the importance of rescue Awareness, Operations, and Technician1 level training among the ranks of fire department personnel and of the effectiveness of multitiered response by highly trained and experienced rescue companies, USAR units, and other specialized resources to help ensure the safety of first responders while increasing the effectiveness and timeliness of rescue and recovery operations.2 Finally, it’s a reminder that technical rescues are rarely “simple and straightforward”; often hidden dangers and life-threatening conditions compel or tempt first responders to deviate from strict orthodox tactics. Sometimes, first responders are compelled to take extraordinary risks to evaluate a situation or attempt a rescue under conditions that would normally require additional equipment, training, and stabilization. In many ways, that is the nature of our business.


(1) USAR personnel size and cut shoring material at the hastily-constructed cutting station. (Photos by Troy Case.)
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    (2) As a camp crew (on right) moves spoil pile material and clears the edge of the excavation to facilitate safer operations, USAR personnel begin stabilizing the excavation wall with preliminary pneumatic shoring (beginning at one end and working their way toward the buried victim). When this photo was taken, firefighters had dislodged the unstable section of excavation wall onto the already-buried victim, who had been pronounced deceased by paramedics before a secondary collapse buried him above his head. Note the equipment pool being assembled in the upper part of the photo.

MISHAP BURIES WORKER

On the morning of June 9, 2003, a construction worker was buried alive by the “shear-in” failure of a nonshored trench that had been dug in the bottom of an unprotected hillside excavation3 in Diamond Bar, California. The fatal collapse occurred at a home construction site in an exclusive hillside development within a guard-gated community 20 miles east of downtown Los Angeles. A 12-foot-wide, 15-foot-deep excavation had been dug into the slope of a steep hillside for the installation of a retaining wall, and a four-foot-deep trench had been cut along the length of the excavation’s floor for placement of utilities.

At least one man was working inside the trench-within-the-excavation, which placed him nearly 20 feet below grade. Neither the excavation nor the trench had been shored (an obvious violation of state and federal worker safety regulations).4 For reasons still undetermined as of this writing,5 part of the wall on the “uphill” side of the excavation suddenly collapsed and buried the victim above his head in heavy clay soil.

Complicating the situation was the steep hillside construction site and a swimming pool filled with thousands of gallons of water perched six feet away (uphill) from the edge of the excavation, a factor that may have contributed to the original collapse and several secondary cave-ins. The weight exerted by the pool and the potential for water to leak into the excavation walls from damage after the initial collapse posed a continuing threat to firefighters attempting to rescue the victim, who was buried deep in the trench and beneath the base of the failed wall.

Further exacerbating the victim’s predicament were the heavy clay (Type A) nature of the soil and its high moisture content, which was tightly compacted around the victim6; difficult access to the rescue site; a long delay by his coworkers in notifying the fire department; a three-alarm fire at which the firefighters assigned to the closest USAR unit were engaged at the time of the collapse; a large shear crack in the uphill wall of the excavation; and the possibility that the collapse might have been caused by a larger geological failure that could precipitate a wider-scale collapse of the steep slope. Finally, there was the remote but ever-present potential for an earthquake to strike at a critical moment (a factor that must always be considered by prudent rescuers and supervisors during high-risk emergency operations at unstable structures, caves, tunnels, trenches, and excavations—and even burning buildings—in Southern California and other seismically active locales).

According to initial reports, panicked coworkers, supervisors, and family members who had been at the work site when the accident occurred failed to notify the fire department for nearly 20 minutes while they desperately attempted to dig the man out with shovels and bare hands. By the time someone called 9-1-1, the coworkers and family members were close to uncovering the man’s face, but it was already too late.


(3) Firefighters prepare to begin shoring after dislodging an unstable section of excavation wall (on left). The victim, who had previously been pronounced dead and was then buried by the first secondary collapse, remains buried in the center of the debris pile, at approximately the place where the trench intersects it. A fractured section of excavation wall remains clearly visible. Note the proximity of the swimming pool to the unstable wall.
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(4) With the large section of unstable wall brought down and some basic shoring in place at the mouth of the excavation along with the standard ladders for emergency exits and lookouts in place, personnel begin digging by hand.
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RESPONSE

The County of Los Angeles (CA) Fire Department (LACoFD) received a 9-1-1 call for a trench collapse with a trapped worker at 8:09 a.m. LACoFD’s Fire Command and Control Facility (FCCF—the department’s dispatch center) responded a standard first alarm “collapse” assignment consisting of two engines, one truck company, one USAR task force, one haz-mat task force, one paramedic squad, one ambulance, and two battalion chiefs. (USAR Task Force 103, the closest technical rescue unit, was committed to a three-alarm fire at the time of the trench collapse, so the next-closest USAR company—USAR Task Force 134—was dispatched with an ETA of one hour.)

En route to the incident, first-due Battalion Chief Mike Saenz (Battalion 12) recognized the extended ETA of USAR Task Force 134 (because the normal first-due task force was assigned to a three-alarm fire7). Therefore, he special-requested a mutual-aid response of USAR Truck 34 from neighboring Orange County’s Fire Authority. Recognizing lessons learned during many previous successful trench rescue operations over the years in L.A. County, Saenz also requested three commercial-grade “hydro-vac” industrial-grade dirt vacuums from L.A. County Public Works8; two LACoFD USAR trailers9; and one LACoFD wildland firefighting camp crew for extra staffing and shoring support.10

On arrival, first-due Engine 119’s Captain Doug Brickey and his crew (including two firefighter/paramedics and a two-year firefighter who had recently completed a state-certified Emergency Trench Rescue course conducted by the LACoFD) made their way several hundred feet to the back of the home under construction where the collapse had occurred and quickly sized up the rescue problem. They found three coworkers in the excavation trying to assist a man who appeared lifeless, cynanotic, and firmly entombed nearly chest-deep in moist, hard-packed clay soil. Some of the man’s family members were also at the scene and were obviously distraught.

Brickey established incident command, identified a staging area for incoming units, and requested the response of an LACoFD air squad (a fire/rescue helicopter staffed with a pilot and two firefighter/paramedics) to expedite victim transportation to a trauma center. Then Brickey directed the workers out of the excavation to prevent additional victims in case of collapse and to determine critical information (such as the total number of buried victims, their last known location, what they were doing when the collapse occurred, and the presence of gas or water lines). Meanwhile, his crew established a 50-foot exclusion zone and a 150-foot operational zone. Brickey also ordered that a support zone be established in a 300-foot perimeter and all vibration-causing equipment in the area be shut down.


(5) USAR personnel hand-dig material away from the pile that covered the victim. Note the tag lines and emergency exits.
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(6) As firefighters close in on the victim, they dig by hand and use small hand tools to avoid unnecessary trauma to the victim’s body. This approach is equally valid for live and dead victims; in fact, it’s perhaps more important for live victims because hand-digging may prevent injuries or further airway obstruction.
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A CRITICAL DECISION

Naturally, the workers (including the work site supervisor) had been reluctant to leave their trapped colleague. The firefighters convinced the man’s coworkers and relatives that it was excessively dangerous to reenter the excavation before it could be properly shored and that to do so might make the situation worse for their colleague by diverting attention to the rescue of other people if there were another collapse.

Having removed the victim’s coworkers from the excavation, Brickey found himself under pressure to immediately deploy firefighters to continue unburying the man. There was clearly a need to quickly determine the victim’s condition so appropriate tactics and strategies could be developed based on a realistic risk-vs.-gain equation. Brickey was aware of prohibitions against firefighters and other rescuers entering unshored trenches (even to conduct rescue operations).

Brickey was faced with a three-part problem that commonly confronts first responders at these incidents: First, there was no rapidly deployable shoring evident at the scene (the excavation walls were too high for normal shoring methods, anyway). Second, except for one firefighter who had just finished the trench rescue course the previous week, the level of training of his personnel was limited to Confined Space/Trench Rescue First Responder Awareness. Third, the closest USAR unit was at least 15 minutes away.

He quickly conferred with his crew. Lacking any obvious choices for effectively stabilizing a 20-foot-deep excavation trench in time to create a reasonable safe zone for firefighters to reach the victim’s side and evaluate his condition, he found himself in a “catch-22”: He knew there was a greater than 50 percent chance of secondary collapse following initial collapses in trenches and excavations, and it was necessary to stabilize the excavation wall through extensive shoring. But they also had a potentially viable victim whose only hope was for firefighters to rapidly extract him, and it was evident that shoring up the excavation would require equipment and USAR-trained staff responding from distant locations.

Brickey concluded that he had no “good” choices and his best chance was to select the “least-worst” option. He determined that he would employ LCES (Lookout, Communication, Escape Route, Safe Zone) protocols and cautiously enter the excavation with two firefighters (one a paramedic) and an automatic external defibrillator (AED), oscilloscope, and trauma pack, to determine the victim’s medical condition (rescue or body recovery operation?). The two remaining firefighters would be a rapid intervention crew. The victim’s condition would determine the level of urgency and the degree of risk to be taken.

Brickey passed command to the next-due engine and reviewed the LCES parameters with his crew. Wearing wildland firefighting gear, they cautiously entered the open end of the excavation and made their way to the victim. They found that the man was extremely cyanotic, pulseless, and nonbreathing, with a mouth full of dirt and evidence of severe crushing forces continuing to squeeze his body (bulging veins and eyes). While one firefighter attached a hose strap and a tag line to the victim’s body (to expedite locating him if he was reburied), the others applied the AED leads. The AED indicated a nonshockable rhythm and the oscilloscope confirmed a-systole.

Given the circumstances of the entrapment (the severe nature of his burial; the evident long-term nature of his pulseless and nonbreathing state; the long delay in notifying the fire department; the continuing crushing forces on the victim; the imminent danger of secondary collapse that would remain until substantial shoring systems could be erected; and the length of time it would take to extract him) and small rivulets of soil that the rescuers noticed coming off the wall of the excavation, it was apparent that the victim was not medically viable and that no lives should be risked to extract him. This was confirmed by the paramedic base station, which concurred with the decision to pronounce the victim deceased.

SECONDARY COLLAPSE

Once the determination was made, Brickey and his crew immediately exited the excavation, trailing the victim tag line behind them, and gave a follow-up radio report to Dispatch. Battalion 12 Chief Saenz was on-scene and assumed command. Saenz requested the coroner’s office to respond, and he also requested notification of the L.A. County District Attorney’s Office, which has a countywide policy of investigating all workplace safety deaths and serious injuries.

Suddenly, the “greater than 50 percent chance of secondary collapse” statistic cited by OSHA proved (once again) to be accurate when a large secondary collapse occurred, completely burying the victim in compact soil well above his head. The “uphill” wall had sloughed away just below the swimming pool, which was obviously exerting major forces on the excavation walls and threatening more collapses. The area that was now buried included the place where firefighters had been standing to assess the victim just minutes before. In the performance of their duties, the members had clearly dodged the proverbial bullet, and they knew it.


(7) With the deceased victim’s head covered, firefighters use small hand tools and bare hands to uncover him so he can be extracted in the most respectful manner under the circumstances.
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    (8) Components of the flying raker shore (which had to be extended and braced against a vertical excavation wall) are visible above the heads of rescuers the shoring is protecting from secondary collapse of the highest excavation walls. Note the expanding cavity as firefighters remove soil from around the victim’s body. This graphic photo is instructive for those who have never dug a victim out of hard-packed soil: Regardless of whether the patient is alive or deceased, it’s usually necessary to remove the soil from around the entire body—right down to the heels of the feet—before the victim can be removed, to avoid causing further injury or damage. This is the reason trench and rescue operations often are time-intensive. This is also the reason the tactic of “vertical extraction” (establishing a raising system, securing the victim in harnesses progressively as parts of his body are unburied, and raising him vertically out of the trench or excavation) is commonly used by the LACoFD and other progressive agencies.

INCIDENT ACTION PLAN (IAP)

Other first-alarm units were now arriving in staging and were assigned to enter the support area with their personal protective equipment in expectation of engaging in a long-term shoring and recovery operation. Second-due Battalion Chief Thom Page arrived and was assigned as the operations chief. OCFA USAR Truck 34 arrived soon thereafter. Its captain was assigned as rescue group leader; the rest of his crew was designated to provide technical assistance and to begin to develop a shoring plan with staffing from LACoFD Truck 118 and Camp Crew 2-2.

Squad 119’s firefighter/paramedics were designated as the Med-ical Group (in case of injuries to rescuers) and were joined by LACoFD Medical Director Dr. Frank Pratt, who is typically dispatched to major rescues and multialarm fires. The air squad was assigned to a nearby landing zone in case of injury to rescuers that may require medevac transport to a trauma center.

USAR Task Force 103 had picked up from the three-alarm fire and was now responding to the excavation collapse with a 30-minute ETA. With two LACoFD USAR task forces and OCFA’s USAR Truck 34 on-scene, there would be at least 20 rescue technicians to conduct the technical operations and provide for personnel rotations (typically the LACoFD USAR officers use 30-minute personnel rotations for shoring, cutting, digging, and breaching operations in confined areas like trenches) and rapid intervention. This was in addition to the other first responder firefighters and camp crew personnel who were prepared to conduct assorted tasks, staff the Medical Group, cut and move shoring materials, and so on.

Based on confirmation that it was a recovery and the likelihood of additional collapses of the unstable uphill wall onto the rescue site, Saenz established an Incident Action Plan (IAP) that would include extra precautions to ensure maximum personnel safety and redundant safety to avoid further collapse or entrapment. It would also address such issues as logistics, rehab of personnel, liaison with law enforcement, providing timely information to the news media (already reporters and cameras were on the ground and in helicopters circling the incident), and critical incident stress debriefing and support for the victim’s relatives and coworkers.

Within the IAP was a rescue plan developed by the USAR captains. Their primary strategy was to stabilize the excavation to prevent collapse onto rescuers; create a series of safe zones leading to the victim’s location, which would allow entry teams to begin unburying the victim using hand tools; provide for personnel accountability and rapid intervention capabilities in case of an “adverse event”; extract the victim without causing further damage to his body; preserve evidence for investigation by workplace safety investigators and law enforcement; gradually retreat from the excavation while taking out permanently assigned shoring devices (e.g., pneumatic shoring systems, and so on) in reverse order in a way that ensures maximum personnel safety; and secure the site for investigation and to prevent anyone else from becoming trapped.

The IAP and rescue plan included several contingencies in case of unexpected events such as secondary collapse causing entrapment of firefighters, injuries to firefighters, rupture of water mains or other utilities, and failure of equipment. In anticipation of shoring and entry operations (and to comply with applicable worker safety regulations), personnel lowered ground ladders into the excavation to provide escape ladders every 20 feet. There was not yet sufficient material to place edge protection, but personnel were ready to get this going as soon as the first USAR trailer arrived.

Haz-mat personnel lowered monitors into the excavation to check for contaminants and continued monitoring throughout the incident. The atmosphere in and around the excavation was found to be clear; since generators were running on the street at the rigs (far from the rescue site), there was little chance of carbon monoxide from exhaust migrating to the excavation. There did not appear to be any hazard from utilities in the ground near the excavation.

Meanwhile members began shoveling a spoil pile back from the edge, per normal procedures, to reduce the weight on the sides and to prevent the pile from sliding into the hole.

When USAR Task Force 134 arrived, members helped determine the shoring scheme for the unusual dimensions of this excavation (with its three-foot-deep trench within it).11 Soon thereafter, the first USAR trailer arrived, increasing the available shoring material.

To begin shoring operations, a rescue team identified as Team 1 was established, consisting of firefighters from USAR Task Forces 134 and 103 (which had just arrived), each wearing standard collapse PPE and equipped with harnesses to which tag/tracer/retrieval lines were attached (to more quickly locate each member in case of secondary collapse). A rapid intervention crew was established. The incident safety officer and the USAR safety officer would continuously evaluate the operation as it progressed, ensuring that the risk- vs.-gain equation remained appropriate for the recovery of a deceased victim.

An LACoFD chaplain responded to the scene. The family and coworkers already had been moved to a safe distance out of the support zone and were continually updated by the chaplain about the operation and what to expect next.

The public information officer had established a media area outside the support zone and was keeping the press informed of the developments and operational details. This included keeping hovering news helicopters at a distance to maintain clear voice communications at the scene.

SAFETY BRIEFING

IC Saenz conducted a safety briefing for all personnel. In accordance with normal protocol for high-risk operations, the LCES protocols were reviewed:

Lookout consisted of the safety officers and other personnel positioned to maintain constant observation of the excavation wall and other potential hazards. A private soils engineer who had been involved with the construction project was on-site and continuously evaluated the excavation walls to warn of potential secondary collapse.

Communications were relatively uncomplicated because most of the personnel were in visual and voice contact throughout the operation. Therefore, communication would naturally include “face-to-face” interaction, voice contact between rescuers and command, port-able radios, and PASS devices carried on team members, as well as a written IAP.

Escape Routes had already been established, including foot travel through the “open” end of the excavation and several escape ladders placed at the requisite distances for trench rescue operations.

Safe Zones had been established just outside the collapse zone of the “uphill” excavation wall and the open end of the excavation. Additional shoring would reduce the collapse potential and the distance required for rescue team members to reach a safe zone.

In addition to LCES, personnel accountability would include a Confined Space Rescue Entry form, which would include a constantly updated list of personnel in the excavation, as well as trench/excavation-specific measures such as tag/tracer/retrieval lines.

SHORING OPERATIONS

Now shoring operations began in earnest. Firefighters and camp crew members had been shuttling shoring material through an estate-sized yard and down a path to the open end of the excavation, where a shoring pool had been created.

A cutting station (with a cutting table built just outside the support zone to reduce the noise of sawing operations at the rescue site) was established. The second USAR trailer arrived with more shoring material.

The first stabilization efforts were targeted at placing edge protection around the perimeter of the excavation to prevent “point loading” that could cause walls to collapse. Then, in typical style for collapses (working from the “shored” to the “unshored” areas), the firefighters began working from the safe zone at the open end of the excavation and extended it by working their way (shoring the excavation walls as they went) toward the buried victim’s position.


(9) The flying raker shore, a drain line, the unstable excavation wall that collapsed at least three times, and the swimming pool beyond are visible above the heads of rescuers.
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(10) After extraction, the victim, covered and secured in a rescue litter, is carried out of the excavation and transferred to the custody of the coroner’s office.
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“PREEMPTIVE COLLAPSE” STRATEGY

USAR Engine 103 Captain Dave Norman (designated as the USAR safety officer12 to augment the assigned incident safety officer) closely observed the shoring operations. Throughout the incident, firefighters and officers had shared concern about the potential for an even larger chunk of the “uphill” excavation wall to collapse onto personnel digging for the victim (after all, there had already been one “close call” in a secondary collapse that might have buried firefighters that morning if they had not evacuated the area after the new firefighter’s timely warning). Given the fact that this had become a body recovery, it was naturally important to ensure that extra precautions were taken to prevent further injuries or deaths.

When a stress crack was found in the uphill wall of the excavation, Norman called “All Stop,” and the shoring operations ceased until the potential hazard could be evaluated.13 All personnel who had been placing shoring below the wall were moved out of the potential collapse zone while officers inspected the crack more closely.

It became apparent that the crack was gradually lengthening and widening, a reliable indication that a secondary “shear-in” collapse might be imminent. The segment of wall that would likely fall was sufficiently large so that it might bury rescuers beneath tons of soil. Naturally, it required some sort of stabilization before personnel could be allowed back in that section of the excavation.

Tying back the unsecured wall was not a pragmatic or timely option because the offending material was soil (the tie-back method was used with a huge concrete slab at the Oklahoma City Bombing site that was threatening rescuers). In addition, there was some concern that the swimming pool (filled with water and sitting above and just six feet from the edge of the excavation) was exerting excessive pressure on the “uphill” excavation wall and the growing stress crack was the most visible symptom.14

The firefighters asked the soils engineer if it might be helpful to empty the pool using portable pumps carried on all LACoFD engine companies (for obtaining firefighting water during earthquakes, major wildland/interface fires, and other disasters).15 The idea was to drain the pool and direct the water down the gutter on the paved street at the front of the property. The soils engineer cautioned against pumping the pool dry, explaining that it might cause the reinforced concrete shell of the pool to “float” or even to “pop out” of the ground intact as it was “unweighted.” The effect, he said, might be similar to that of a coffin that violently rises to the surface when a cemetery is flooded and drastically changes the pressure differentials. In the engineer’s view, pumping the pool risked making the situation even more unstable than it was. The decision was made to hold off on that idea.

After considering several other options for removing the offending slabs of soil, Command concluded (with concurrence from the engineer) that the best solution would be to dislodge it from the excavation wall to eliminate (or reduce) the overhead hazard. In essence, it would be a “preemptive collapse,”16 purposely caused by rescuers to eliminate a hazard.

The main dilemma of this solution was that it would drop several more tons of soil onto the already-buried victim, but the officers agreed that dislodging the unstable section of wall would be the best way to eliminate a hazard that threatened the lives of rescuers attempting to unbury him. The officers felt the danger to firefighters who would be digging out the victim at the base of the uphill wall, in the midst of the collapse zone, outweighed concerns about the impact another collapse would have on the deceased victim.

Naturally, even this operation would have its risks, which Command would attempt to reduce through the use of redundant safety measures. For example, it was decided to secure a firefighter to a belay line anchored near the pool and have him work from above the excavation to dislodge the soil with a long plank that he could wedge into the crack and use like a pry bar. It only took a couple of sharp jabs to dislodge about four tons of earth, which crashed down into the excavation and further buried the deceased victim.

The entire excavation site was once again examined for telltale signs of additional collapse. The soils engineer was asked to evaluate the stability of the excavation wall, and he pronounced the area reasonably safe to work in. Still, there were continuing concerns about the stability of the wall beneath personnel who were going to be digging in precisely the same location where the previous “close call” had occurred.

Therefore, as personnel prepared to resume the process of uncovering the victim, the possibility was discussed of shoring the wall in a way that would prevent (or, at least, slow) another collapse or allow sufficient warning (the telltale sound of wood shoring systems creaking, for example) for firefighters to retreat before it came down.

FLYING RAKER SHORING ESTABLISHED

With the large threatening section of overhead excavation wall having been dislodged and knocked off, shoring operations continued with the goal of securing a safe zone around the victim so digging could begin in earnest. Pneumatic shoring systems were used to help support unstable walls, but there were still concerns about the stability of the remaining “overhead” section of excavation wall and the potential for it to collapse on the victim and rescuers. After assessing the situation in the excavation, the shoring officer came to the conclusion that a flying raker, typically used to help stabilize the walls of buildings and other more conventional structures damaged by earthquakes, explosions, and other forces, could be installed in such a way that it would keep the upper sections of the excavation wall from collapsing further or at least give rescuers warning so they could move out of the collapse zone.

None of the personnel had heard of a flying raker being used in an excavation, but that didn’t mean it wouldn’t work. The system was unorthodox, but it did the job. Once the shoring officer and the other rescuers were satisfied with the stability of the wall, they turned their attention to uncovering and extracting the victim.

VICTIM RECOVERY

Team 1 reentered and secured a drainage pipe before once again digging by hand for the victim. Normally, the firefighters would have attempted to expedite the process of digging out the victim through the use of at least one air knife (a long wand that directs high-pressure air to break up the soil) and a dirt vacuum (a long vacuum tube designed to extract large volumes of loose soil). Through recent decades of experience handling many trench and excavation rescues, fire departments across the nation have demonstrated the usefulness of these devices, augmented by industrial-sized hydro-vac systems for unburying victims.17 In this case, it would have been helpful by reducing the exposure of the firefighters digging around the victim.

Unfortunately, it was determined that the hydro-vac commercial vacuum trucks would not be useful for this incident because the distance from the driveway and street to the excavation exceeded the length of hose carried on the trucks. And the rescuers agreed that the smaller dirt vacuums carried on both LACoFD USAR apparatus might not be practical for this particular operation because of the large amount of material that had to be removed. Consequently, the firefighters dug with hand tools and shovels. The diggers wore full-body rescue harnesses; tag lines (as well as other standard precautions) were used where appropriate.

The victim’s recovery was planned to take into account such issues as chain of custody, preventing unnecessary trauma to the man’s body, and reducing emotional trauma to the friends and family. To this end, a blue cloth was kept ready to cover the victim’s head as it was exposed and a disposable blanket and rescue litter were positioned to expedite covering him after extraction. Similarly, there was a game plan for allowing investigators to photograph the rescue scene and the victim during the recovery and to transfer the victim out of the excavation to the coroner’s vehicle with a minimum of exposure to the public eye.

Because the victim’s exact position wasn’t fully known after the second collapse, firefighters followed the tag line and dug gingerly until they located him. Then the rescuers concentrated on removing the soil near his body and preparing for a vertical extrication using the webbing strap. The idea was to limit the exposure to secondary collapse by removing only the soil required to free the body, which would essentially leave a cavity in the dirt. It doesn’t always work that way (depending on soil conditions and other factors), but it’s a proven approach that limits time “in the hole.”

As planned, the man’s head was covered with the blue cloth once he was unburied to the neck. As is typically the case in trench collapses, uncovering the body was a lengthy process because of the tight working spaces, compressed soils, and need to uncover practically every square inch of the body (down to the heels) to free it sufficiently for removal without causing bone fractures and other injuries. The tag line and hose strap were helpful in maneuvering the body, which was placed in the rescue litter and covered before being secured. Then firefighters carried the victim from the excavation and transferred him to the custody of the coroner’s office.

While equipment was being rehabbed, some firefighters were assigned to accompany investigators into the excavation to take scene photos. After the scene was secured and turned over to investigators, Saenz held a brief post-incident review at the command post.

LESSONS LEARNED

First responder (Awareness or Operational) training for trench rescue and other common technical rescues is critical to the safety and effectiveness of fire departments. Operations Chief Page explained: “These types of incidents are sometimes perplexing for the first responders. The ‘risk-vs.-gain’ scenario put the first responders in a dilemma at this incident. As a battalion commander, it is wise to discuss/practice these types of situations with your company officers on a regular training basis. Know the capabilities and experience of your officers. You do not want them conducting an operation based on a misunderstanding of your incident expectations. Let your officers know that it is okay and prudent to say ‘no’ sometimes. There is enough pressure as it is.”

The general prohibition against entering an unshored trench or excavation places first responders in a “catch-22”: While the first-arriving firefighters might understand it’s against the rules to enter before proper shoring can be installed, they may be in direct visual and voice contact with victims whose only hope is for firefighters to immediately enter and begin unburying them. In cases where the victim is fully buried, the situation is actually more grave and the need for immediate action more urgent. We must ask ourselves what is prudent. For example, if the closest USAR or rescue company is 20 to 40 minutes away, are first responders really expected to stay out of the hole and delay direct digging to unbury a victim’s face or chest? This incident demonstrates the nature—and sometimes the dilemma—of the firefighter’s job: Occasionally there is an overriding need to take certain calculated risks to save a life (or, in this case, to determine whether the victim is savable, which will dictate the level of acceptable risk). This may sound like heresy to some purists who insist that no one should enter an unshored trench or excavation deeper than five feet under any circumstance. In some ways, this is a gray area—an area in which the most difficult decisions are made by those whose role it is to enter the potential collapse zone to save a life.

The need for technical rescue planning (including knowledge of local and regional resources) was made evident by this incident. It’s critical that ICs understand how to ensure the response of rescue companies (or USAR units), shoring material units, helicopters (for more timely trauma center transportation of freed victims), hydro-vacs, air knives, and other specialized equipment and personnel. As this incident demonstrated, simultaneous major emergencies can strip specialized units that would otherwise be required to conduct technical rescues; therefore, the IC needs to be prepared to request mutual aid and take other corrective measures.

Once a trapped victim is deemed nonsavable, the level of risk for responders should be lowered accordingly. There is absolutely no reason to lose the lives of rescuers to recover a deceased victim.

Organized and highly experienced rescue companies and USAR units are critical during high-risk (and highly technical or unusual) incidents such as this. The ability to improvise workable solutions for unexpected problems is directly related to the rescuer’s base knowledge about the hazard, his basic training about how to handle the hazard, and his experience in dealing with variations of it.

The incident command system is effective in organizing and managing such technical rescues. “Order and procedure need to be the rule. This type of incident needs careful thought just like any technical rescue does. Proper setup and control of the operational area are musts for the safety of all parties. This type of incident requires extreme teamwork and cooperation from all involved,” Page concluded.

Endnotes

1. Refer to NFPA 1670, Operations and Training for Technical Rescue Incidents, and NFPA 1006, Professional Qualifications for Rescue Technicians, for training requirements for USAR/Rescue Awareness, Operations, and Technician levels.

2. According to NFPA standards, personnel at the Technician level must be able to recognize rescue-related hazards and use the equipment and methods necessary to conduct, coordinate, or supervise a rescue operation. Rescuers at the Operations level should know how to use search and rescue equipment to safely and effectively participate in the rescue. Operations-level rescuers are qualified to conduct search, rescue, and recovery operations under the supervision of rescue technicians.

3. A trench is generally defined as a narrow excavation not deeper than 15 feet and deeper than it is wide, whereas excavations are man-made cavities or depressions in the earth’s surface, wider than deep and sometimes exceeding 15 feet in depth.

4. Some fire departments make a practice of reporting unsafe conditions like nonshored trenches when they are observed. To prevent mishaps that might later endanger firefighters and other rescuers, it is prudent for firefighters to order workers out of nonshored trenches and excavations that clearly violate worker safety regulations, secure the site for later investigation, and request the response of a representative of the jurisdictional worker safety agency to address the situation in a way that ensures reasonable safety for workers and prevents the need for firefighters to be placed in life-threatening conditions if a nonshored trench or excavation collapses on people. Although there is no written policy for this specific situation, these steps listed above have been taken by LACoFD first responder units in recent years, and it may have saved lives. This approach may be viewed as controversial in some quarters, but it is clearly consistent with the fire service’s main mission of protecting lives.

5. This fatal accident and its aftermath are currently under investigation by the California Occupational Health and Safety Agency (Cal-OSHA), the Los Angeles County District Attorney’s Office, and the L.A. County Sheriff’s Department.

6. Type A soil is described as cemented or cohesive clay, silty clay, clay loam, with an unconfined compressive strength of 1.5 tons per square foot (tsf) or greater, which clumps easily and has other characteristics that make for difficult extractions after collapse occurs. Type B soil (the most deadly) is described as cohesive angular gravel, silt, loamy sand with an unconfined strength between 0.5 tsf and 1.5 tsf, which also clumps easily. Type C soils include granular gravel, sand, and loamy sand with an unconfined strength less than 0.5 tsf. Type C soils also includes submerged or “free seeping” soil, or steeply sloped soil, which breaks apart easily. The fourth category is rock.

7. At this point, Dispatch notified the incident commander of the three-alarm fire to which USAR Task Force 103 was assigned and asked whether he might be able to release the USAR unit to respond to the trench collapse. Because initial reports indicated a “working” trench rescue, with the obvious need to get rescue-trained resources to the scene quickly, the IC released Task Force 103 and reassigned another unit in its place. TF103 personnel quickly began taking up to respond to the trench rescue.

8. The request for three hydro-vac trucks has become a standard request from LACoFD units responding to trench and excavation collapses because it has been found that this equipment is helpful in stabilizing the scene and removing soil to unbury victims in tight spaces. The first truck goes to work, and the second truck is positioned (with hoses deployed) to allow firefighters to continue uncovering victims when the first truck’s vacuum storage tank becomes full (at which time that truck must pull out and dump its load somewhere). The third truck is requested to be put into the rotation in case of mechanical failure of either of the first two trucks. This may seem like overkill, but in fact it has been demonstrated to be a prudent move during high-risk life-saving operations like trench/excavation collapses, when every second may count.

9. Each USAR trailer is equipped with shoring materials, pipe shores, and other materials for collapse operations and is towed by a heavy duty “stakeside” utility truck from the battalion to which it is assigned. The LACoFD has seven USAR trailers, one assigned to each division.

10. LACoFD camp crews are trained in Rescue Systems I and high-angle rescue, a move intended to increase their ability to rescue colleagues in wildland mishaps in hostile terrain and to increase their utility during earthquakes and other disasters.

11. Later, the rescuers would include an improvised flying raker shoring system to support the unstable excavation wall, a somewhat unorthodox use of shoring originally designed for quake-damaged structures that proved to be quite effective in this case.

12. In addition to the LACoFD safety officer’s position, all captains assigned to the LACoFD’s Training Services Section are also assigned as incident safety officers, based on a “duty” rotation that ensures 24-hour availability of safety officers for multialarm fires, prolonged technical rescues, and other major incidents. At the scene of “working” technical rescues, the incident safety officer is usually augmented by a USAR-trained officer assigned as the USAR safety officer, whose role is to oversee safety of technical operations like confined space entry, the operation of high angle rescue systems, etc.

13. It’s standard practice for all personnel to immediately halt operations and determine what the problem is whenever the safety officer (or, for that matter, any other member at the scene) calls “All Stop” or gives a single blast of a whistle or air horn to get everyone’s attention.

14. It seemed logical to assume that the weight of the swimming pool may have contributed to the initial collapse that killed the worker, as well as the secondary “shear-in” that reburied him minutes after members conducted their operational retreat.

15. The pumps were implemented after the devastating 1993 firestorms, in which hundreds of homes burned in Malibu and in the Kinneloa (Altadena) fires, where the hydrants went dry because of power outages that eliminated pumping stations in neighborhoods where fire was blowtorching through. The pumps are on every engine company.

16. This is consistent with a hierarchy of options applied to many collapse hazards: If you can eliminate the offending hazard, do so. If you can’t eliminate the collapse hazard, then secure it or shore it. If you can’t eliminate, secure, or stabilize the hazard, then avoid it.

17. The LACoFD’s USAR apparatus are equipped with rescue-size models and have been using the commercial-grade hydro-vacs for trench and excavation rescues since 1991. In many instances, these tools have helped cut the rescue time in half. They are a proven solution for many situations where victims are buried by soil and other materials.

LARRY COLLINS is a 24-year member of the County of Los Angeles (CA) Fire Department (LACoFD). He is a captain, USAR specialist, and paramedic assigned to USAR Task Force 103. He is a search team manager for the LACoFD’s FEMA/OFDA USAR Task Force for domestic and international disaster response, and he served as assistant task force leader at the Northridge earthquake. He is a USAR specialist on the “Red” FEMA US&R Incident Support Team and sits on a number of local, state, and national committees. He is a frequent instructor at conferences and author of the three-part book series Technical Rescue (Fire Engineering).

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