Author’s note: The catastrophic failure of the heavily traveled I-35 West bridge in Minneapolis on August 1 once again highlighted the importance of a robust multitiered, multihazard emergency response; highly adaptable emergency plans; and a thorough understanding of collapse search and rescue protocols by firefighters and other responders.
The I-35W collapse response was complicated by deadly water hazards that challenged responding firefighters. The I-35W bridge was loaded with cars, trucks, and at least one school bus that plunged into the Mississippi River. The combination collapse and water rescue operation challenged first responders and ultimately required specialized rescuers and equipment from local, regional, state, and federal agencies working within a unified command for many days. The disaster also highlighted the importance of having in place an effective system for using off-shift personnel to quickly augment on-duty resources.
The consensus is that the overall response to this collapse was very effective in terms of deploying local resources to save lives; bringing to the scene the best available specialized help from around the region, state, and nation in a timely manner; and ensuring the best possible degree of rescuer safety under extremely dangerous and unusual conditions. This multipronged response, which involved all levels of government working in tandem under unified command, is an example of the new paradigm of disaster response in the United States. Today, the public has (rightly) come to expect integrated and multilayered response in times of disaster, and the Minneapolis fire and police departments delivered it on August 1.
BY LARRY COLLINS
Historically, water hazards are a surprisingly common factor in major collapse search and rescue (SAR) operations worldwide and something we need to consider whenever we’re dispatched to a collapse emergency. In some places, the likelihood of encountering water hazards in a collapse emergency should be built into local plans. Incident commanders should be prepared to incorporate water rescue teams, dive teams, and other water SAR capabilities into the overall response. The severity of the water rescue hazards will dictate the level of response and the need for highly specialized teams.
When large structures collapse with people inside (or beneath or on top of them), rescuers are confronted by unique challenges that sometimes defy conventional approaches and “template” response models. “Grey areas” are typically encountered in the course of multihazard emergencies, forcing incident commanders and company officers to adjust their standard operating protocols to fit the unusual circumstances. The situation is even more dynamic when water hazards are involved in a collapse emergency, because a wide range of additional considerations and tactics are needed. The I-35W collapse in Minneapolis on August 1 is a classic example of this.
This article examines the challenges facing rescuers at structure collapse in the water environment, including structure collapses where water infiltrates the scene, creating water-rescue hazards in the midst of collapse search, rescue, and recovery operations.
As firefighters and rescuers in the midst of what has become a generational wave of radical Islamic terrorism against the West (which complicates the hazard of other domestic and international groups that use terrorism for their means), it’s important to recognize the often unspoken intersection of terrorism and deteriorating infrastructure in our nation.
We would be remiss if we failed to recognize that some terrorist groups may be closely watching as some strands of the fabric of our nation’s infrastructure seem to be becoming undone through normal wear and tear. If the strategy of some terrorist groups includes identifying chinks in our nation’s infrastructure and then planning corresponding attacks to inflict the maximum damage, it follows that some terrorist groups have been watching recent disasters in the United States with interest. This is yet another reason timely and effective response to collapse and other emergencies is critical.
It is not inconceivable that the Minneapolis disastrous bridge collapse and the chaos and destruction it created would lead some terrorist groups to see “force multiplier value” in conducting attacks on other potentially vulnerable bridges, perhaps simultaneously. Given the growing evidence of inherent weaknesses in certain bridge designs and the awareness that a significant number of bridges are becoming vulnerable to collapse from normal daily use, it’s only a small leap for terrorists to conclude that bridges are “good” strategic targets for causing mayhem on a wide scale with relatively little effort.
If there is any positive news from the I-35W collapse, it’s that the response of the Minneapolis fire and police departments and other local and regional responders was very effective and highly coordinated from the beginning. The incorporation of highly specialized underwater rescue and recovery teams from the military and other sources was a hallmark of this response. The I-35W collapse demonstrated that the greater Minneapolis area is well prepared for disaster. As the fire service and other response elements continue to demonstrate their ability to quickly overcome the challenges of such disasters, some terrorist groups may be deterred by the effective response.
EXAMPLES OF COLLAPSE COMPLICATED BY WATER HAZARDS
The I-35W bridge collapse focused worldwide attention on the dilemma of people trapped in waterborne collapsesbut it’s a hazard long recognized by some disaster planners and emergency responders. The collapse of a large bridge into a river, lake, swamp, harbor, or bay is perhaps the most obvious example of a collapse emergency complicated by water hazards. There have been a significant number of multiple-fatality bridge collapses in recent American history, but there are also many other examples of situations in which firefighters and rescuers could be confronted by missing or trapped victims in collapses complicated by water.
Water is by far the biggest killer in hurricanes. Hurricane Katrina in New Orleans was just one of the many recent examples of entire neighborhoods being underwater from hurricanes in this country. History is rife with examples of structures collapsed by the storm surge and winds that accompany hurricanes. In some cases, structures collapse from the winds, trapping victims who then are in danger of drowning when the storm surge and drenching rains arrive. Flash flooding from intense and sustained downpours (especially in mountainous terrain) is yet another problem that occurs in hurricane-affected regions. In the aftermath, SAR operations are complicated by standing and moving water that limits access and endangers rescuers. The large width and breadth of the damage areas, the number of structures potentially involved (hundreds, thousands, tens of thousands, or even hundreds of thousands), and the need for 100-percent search for victims in the damaged structures and vessels further complicate the challenge.
History has shown that structures in the immediate path of a dam collapse are likely to be swept away. Some victims are carried away; others are mixed in with debris that will be deposited downstream (requiring search operations there). But, structures on the borders of the flood may collapse in place, trapping victims alive inside (or in attics or on rooftops) as the flood waters rise and quickly recede. It’s possible for very large modern structures to suffer partial or total collapse in the inundation zone, leaving rescuers with the job of searching through debris, mud, and standing water.
Anyone who saw footage of the 2004 Sumatra tsunami, which killed nearly 300,000 people, should recognize the potential for major structure collapse situations in affected urban areas. Although survivability is generally low for people in the path of a tsunami, there are many examples of survival for people who were in homes, commercial buildings, and even vessels. Recognizing this fact, tsunami plans for populated U.S. coastal zones give the highest priority (after timely evacuation) to 100-percent search of all affected structures and vessels after tsunami impact has occurred. This is certainly the case in densely populated places such as Southern California, where a near-source tsunami could strike the coast in minutes, leaving insufficient time for total evacuation and making search and rescue the next most important priority. It’s also the case in places where even hours of warning prior to arrival of a telesunami is no guarantee that 100-percent evacuation has occurred.
(6) This is an obvious example of water damage to large structures, this time from Hurricane Katrina’s striking the Biloxi area of Mississippi’s coast.
There have been many examples in recent history where massive flash floods collapsed or carried away large buildings and bridges and left people trapped alive in damaged structures filled with water, mud, and debris. Often, flash floods occur in waves, with secondary events even larger than the first (dependent on the weather conditions, terrain, and potential for collapse of natural or manmade dams upstream). This presents a serious additional danger for rescuers, especially at night and in inclement weather, where personnel assigned as upstream lookouts may not be able to observe secondary walls of water approaching (they may hear them first). Flash floods can leave low-lying areas inundated with standing water and some buildings submerged.
Mud and Debris Flows
Similar to flash floods, mud and debris flow typically strike without warning, catching people in the most vulnerable positions, knocking down some structures, and packing others with mud and consolidated debris that quickly harden once the movement stops. The mud and debris make it that much more difficult to reach trapped victims, and removing the mud and debris can destabilize some damaged structures. Also, there is the potential for secondary mud and debris flows that can trap rescuers.
(8) The floating casino (background) that battered buildings and collapsed a three-story hotel with people trapped inside, as the 30-foot storm surge devastated the Mississippi coast.
Sinkholes have been known to swallow people, homes, businesses, and entire neighborhoods. This makes SAR operations a very precarious undertaking that must take into account the potential for the hole to grow exponentially larger or to cause additional collapse as the sides slump in. Sinkholes also undermine adjacent structures and may cause the collapse of tunnels below them. Such was the case in the infamous 1995 Hollywood Boulevard sinkhole, which ruptured a large water main during the realignment of twin subway tunnels 80 feet below, swallowing part of the six-lane street before it finally caused the ceilings of the tunnels to cave in, flushing millions of gallons of water into the subways and almost causing the death of nearly two dozen firefighters and tunnel workers.1
Collapses Later Complicated by Water Hazards
Buildings can collapse and then become flooded by ruptured water mains, storage tanks, and other water sources, trapping victims. In the Mexico City earthquake (1985) and other large urban disasters, reports surfaced of trapped victims (and, in some cases, even would-be rescuers) drowning as lower levels of collapsed buildings filled with water from broken water mains and ruptured water supply tanks.
The ruins of the World Trade Center included many below-grade areas that became flooded from water mains and infiltration of ground water through the damaged lining of the “bathtub” built to keep Hudson River water from seeping into underground parking structures, malls, and the subway system. Firefighters and other rescuers, structural engineers, hazmat specialists, and others had to navigate the flooded areas carefully during operations, sometimes using inflatable rescue boats that had to be carried into the labyrinth.
Many firefighters, trapped by structure collapse during firefighting operations, have drowned in the same water they and their colleagues had poured into the fireground. Many others have had close calls after being trapped by collapses in basements, loading docks, and other areas where firefighting water pools.
(11) L.A. County Fire Department US&R firefighters communicating and supporting teams are attempting to rescue a man in a tunnel where a major ceiling collapse had created a dam that flooded its farthest reaches.
Some buildings collapsed into their basements through liquefaction that accompanied the Great Quake of 1906 in San Francisco, reportedly drowning trapped occupants. In Kobe, Japan, and other cities, residents drowned in collapsed buildings when quake-induced elevation changes flooded streets and buildings. Future urban collapse disasters will surely cause people to become trapped in similar fashion, forcing firefighters and other rescuers to confront extremely dangerous conditions and occasionally face “no-win” situations, including fires that threaten victims who may be drowned during attempts to extinguish them.
(12) The view into the outer reaches of the tunnel (before the dam), with water flowing on the floor. This rescue operation emphasized the danger that water poses in a mine and tunnel collapse environment.
When working in subways, one of the worst nightmares is the ever-present potential for being suddenly inundated by ground water orin tunnels burrowed beneath lakes, rivers, and baysescaped surface water into the tunnels through ruptured liners. Another hazard is a collapse caused by explosions, fires, geological failures, or terrorist attacks. Ruptured high-pressure water mains or storm drains could flood subways. Regardless of the cause, thousands (or even tens of thousands) of people could be at risk and may require high-risk SAR operations in flooded collapse conditions.
Much has been made of the efforts of Minneapolis Fire Department’s Captain Shanna Hansen, who was off duty and responded directly to the scene to assist her colleagues in the early stages of the disaster. News cameras caught the action as she entered the water to conduct a secondary search of submerged and partly submerged vehicles while wearing her uniform and a personal flotation device (PFD) attached to a rope and belayed by another firefighter standing on the collapsed bridge. Other members were conducting similar operations under high-risk conditions. Together, they performed magnificently by all accounts, saving the lives of those who could be saved in the first minutes and hours after the collapse.
(13) This water tank under construction collapsed as 26 workers were pouring the concrete roof. Thirteen workers fell in; three were impaled on rebar.
It’s a fact that in the aftermath of the I-35W collapse, some well-meaning observers expressed concern for the safety of the firefighters conducting those operations. Some personnel were wearing turnouts near the water; others were in the water without the appropriate personal protective equipment (PPE), and divers were engaging in very high-risk search operations. There were discussions in some circles about whether it was appropriate to take such risks without necessarily having all the normal PPE and other precautions usually taken in “daily” water operations. Others noted that these operations required specialized swiftwater rescue and dive teams and suggested that perhaps some of these operations should have waited until such resources were on the scene.
(14) L.A. County firefighters extricating workers impaled on rebar. Fortunately in this case, the tank was empty.
On the other hand, other observers, including me, concluded that Hansen and her colleagues did what was necessary given the potential to save lives at that scene: They relied on their skill and training and used the resources immediately available in a well-coordinated manner under disaster conditions that necessarily compelled them to consider the risk-vs.-gain equation in a context different from that in “daily” emergency operations.
This dichotomy between purists and pragmatists is typical of many disaster situations, where firefighters and other rescuers are sometimes compelled to take extraordinary risks without the normal equipment and backup resources. It’s the nature of disasters that the scarcity of resources forces responders to consider taking additional risks to save lives, even when others might question the wisdom of taking those risks.
This dynamic is especially evident in collapse emergencies complicated by water hazards, because rescuers will necessarily be confronted by additional layers of danger in an already hazardous environment and may take extraordinary risks if there is a possibility that viable victims may be trapped and waiting for someone to locate and rescue them.
(17) L.A. County firefighters training with a hydrovac that could be used to remove water from a trench, an excavation, or a structure collapse.
In combination moving/still water, you can make the argument that the judgment and experience of well-trained rescuers on the scene should prevail with regard to tactics like tag lines for searching vehicles. I would agree with that position.
Searching submerged vehicles carries the extra hazard of entrapment, especially when there is debris in the water after a collapse. And, conducting surface dives (without scuba) has particular hazardsfor example, if you become snagged or entangled under the water, you would have only the air in your lungs and just seconds to untangle yourself, whereas with scuba you hopefully can remain calm and collected and figure out how to get untangled and surface safely. There’s always a risk, but responders and incident commanders must weigh the risk against the potential gain of saving a life in situations such as a bridge full of automobiles collapsing into a major river, harbor, or bay.
Perhaps the most pragmatic target we can aim for is a system wherein first responders are given the basic training and equipment to evaluate and react to the range of waterborne emergencies to which they can reasonably be expected to be dispatched and back them up with secondary responders (rescue companies, US&R teams, dive teams, swiftwater rescue teams) with more advanced levels of rescue training and equipment. This approach allows first responders to do what they need to do with some assurance that the risk is minimized.
And, although standards and operational guidelines are important, it’s also important to avoid being overly dogmatic in any discipline, including technical rescue, and that systems be sufficiently flexible so that rescuers are allowed to “adapt and overcome” without undue hindrance, especially when lives are at stake.
Regarding the shore support at a collapse incident complicated by water hazards, it has long been recommended that firefighters and rescuers whose jurisdictions include water rescue hazards always have the basic equipment aboard their rigs to perform their assigned function (including shore support with tag lines and downstream safety). In a big city (and little ones as well), some units that may not have expected to end up on a water rescue operation sometimes find themselves in that positionconsequently, we sometimes see firefighters in turnouts operating near the water (hopefully with a PFD).
This is especially true in a disaster where units from farther distances that do not have water hazards in their immediate first-response areas may be dispatched and find themselves operating in and around moving or still water. In truth, we’ll probably never get 100 percent of safety measures being used 100 percent of the time, but it’s a good goal to aim for (recognizing the reality of the challenges presented by emergencies).
WATER HAZARDS DURING THE FIVE STAGES OF COLLAPSE RESCUE
At this point, it’s helpful to review the five stages of collapse SAR and discuss how the presence of still-water and moving-water hazards may affect operations. The five-stage approach is the basic strategy used by U.S. and international US&R teams, and it’s still the appropriate approach even when water hazards are involved. Naturally, certain adjustments may be necessary, and that’s where a skilled incident commander makes it a priority to integrate the appropriate resources to make the operations as safe and as effective as possible.
Stage 1: Response, Arrival, Recon
- Information about the structures involved (occupancy, etc.).
- Time of day, day of the week, holidays (effects on occupancy).
- Dispatch information (number of potential victims, cause, etc.).
- Arrival: Establish command and conduct size-up/recon
- Unified command.
- Potential cause of collapse (natural, explosion, flooding, fire?).
- The presence of water hazards and how they should be handled.
- Signs indicating terrorism and secondary devices.
- Signs of radiation, chemical, or biological agents.
- Security and force protection.
- Standard apparatus placement for collapse and other operations.
- Strict fire control precautions (charged hoselines, etc.).
- Eliminate utility hazards.
- Eight-sided size-up and recon.
- Structure triage and marking.
- Initial search operations and marking
- -visual search
- -“hail” search
- -physical search
- -technical search
- -canine search
- -water search, if necessary.
- Assume live victims until proven otherwise.
- LACES (Lookout, Awareness, Communications, Escape Route, Safe Zone).
- Operational retreat signaling.
- RIC and personnel accountability.
- MCI operations?
- Technical specialists (structural engineers, heavy equipment, bomb squad, dive team, swiftwater rescue team, etc.).
- Resource and additional resource needs.
- Incident management teams.
- Departmental units and personnel
- -mutual aid
- -state/FEMA US&R task forces
- -FEMA US&R incident support teams
- -local/state/federal swiftwater rescue task forces
- -dive rescue/recovery teams
Anticipate working with the Federal Bureau of Investigation and law enforcement for evidence collection during search, rescue, and recovery operations if there is evidence of terrorism.
Stage 2: Surface Rescue
- Search/rescue of victims at or near the surface of collapse.
- Rescue of victims trapped by nonstructural elements.
- Rescue of victims on or near surface of water.
- Rescue of submerged/trapped victims if possible.
- Dive search/rescue/recovery operations if the site is also flooded, with personnel properly trained and equipped for the particular hazards (moving water, submerged debris with snags, shifting debris, submerged confined spaces, etc.).
- Continued search operations.
- Controlled use of hand tools, bucket brigades, etc.
- No movement, cutting, or breaching of load-bearing structural members until properly shored or secured by personnel trained to evaluate and conduct shoring.
- Basic shoring to protect personnel and victim.
- Strict scene control and security to eliminate secondary attacks and prevent secondary collapse from uncontrolled operations.
- No heavy equipment on the collapse pile until coordinated by properly trained personnel.
- Prevent crushing of victims trapped below the surface by excessive personnel, uncontrolled operations, and heavy equipment movement.
- Identifying and marking void spaces that must be searched for victims.
- Properly handling deceased victims.
Stage 3: Void Space Search and Rescue
This stage may last hours, days, or weeks.
- Search of void spaces by properly trained firefighters, US&R task force members, and canine teams for victims, additional void spaces, secondary devices, evidence.
- Special measures to ensure safety of rescuers and victims (dewatering, drainage, redirecting flow, etc.) when water hazards create complications.
- Dive search/rescue/recovery operations involving personnel properly trained and equipped for the hazards (moving water, submerged debris with snags, shifting debris due to currents, submerged confined spaces, etc.) if the site is flooded.
- Continued search operations; deeper penetration into voids to detect additional victims.
- RIC, personnel accountability, and operational retreatcritical because rescuers are operating in the most vulnerable positions.
- Continued shoring and stabilization as penetration progresses.
- Treatment of victims found trapped in collapse while they are being extracted.
- Cutting, breaching, and lifting to open and widen void spaces during search.
- Removal of victims through the void access points (more difficult if water hazards are present).
Stage 4: Selected Debris Removal
This stage may last hours, days, weeks, or months.
- Selective debris removal (dissection of structure) after all known void spaces have been searchedmainly to expose more potential void spaces that may be searched for victims not previously detectable.
- Delayering operations using heavy equipment and other tools.
- Peeling away of upper layers to reveal additional void spaces (which must be searched using void space search methods).
- Tight control over debris removal.
- Special considerations if the site is infiltrated with water.
- If the site is flooded, dive operations to sling and rig debris to be moved involving personnel properly trained and equipped for the hazards (moving water, submerged debris with snags, shifting debris, submerged confined spaces, etc.).
- Continued identification and recovery of evidence with law enforcement.
- Recovery of deceased.
Stage 5: General Debris Removal
- General debris removal, after all potential survivable void spaces are searched and there is no reasonable chance of survival for victims.
- Use of heavy equipment.
- If flooded, continued use of specially trained dive teams to rig and sling debris.
- Tight control to prevent secondary collapse and other life hazards.
- Continued search for human remains and evidence, with proper removal.
- If water hazards are involved, search for human remains by swiftwater or diver rescue/recovery teams.
THE “GOLDEN DAY” BECOMES “THE GOLDEN MINUTE”
In recent years, rescuers have learned about a critical post-earthquake benchmark sometimes known as the “golden day.” This is a reference to the importance of the first 24 hours after a structure collapse; after that, the survival rate for trapped victims begins to drop fairly drastically. If trapped victims can be rescued within the first 24 hours, they have a far better chance of survival and total recovery. Every day past the first 24 hours decreases the likelihood of survival, and every day people are trapped reduces their chance for total recovery.
We also know about the “golden hour of trauma,” in which the delivery of seriously injured victims to a trauma center or other appropriate medical facility tends to greatly improve the chance of survival. In a major collapse emergency, it’s typically only the people rescued in Stage 2 (surface rescue) who can be delivered to a trauma center in the first hour. It may take many hours to locate trapped victims and many more hours to rescue them.
With the introduction of water hazards in the collapse environment, we now have another time frame to consider, something that can euphemistically be called “the golden minute.” Victims trapped in a flood or swiftwater environment may have only minutes to be rescued before survivability becomes nil. This is especially true in the case of trapped victims who are also submerged or those trapped in rising water. Victims trapped in these conditions may require a more radical approach than those not trapped in waterand not only for the benefit of the victim. Rescuers may be equally at risk and may also become victims if they delay.
Therefore, the use of “more radical approaches” may include forcing the victim out without delay even if it causes injuries; skipping normal C-spine precautions; making rapid entry and removal without the normal shoring and stabilization that might be required in the nonwater environment; breaching walls to drain water; providing the victim with SCBA or SABA during the rescue to maintain the ability to breath even if the water rises over his head; or possibly even resorting to field amputations to remove victims to safety.
PLANNING FOR SUSTAINED SAR OPERATIONS
Except for the most extreme situations of water hazards that complicate collapse emergencies (e.g., a 30-foot storm surge, a tsunami, a dam failure, or a flash flood that completely submerges the collapse zone), it may be possible to locate and rescue live victims up to three weeks. Therefore, rescuers and incident commanders should be prepared to sustain nonstop SAR operations until all hope of locating viable victims has passed.
It’s not necessarily hopeless for victims missing or trapped longer than a day. In fact, many people have been rescued alive after three to four days of entrapment, and some survivors may be found up to 16 days after the event. The bottom line is this: Firefighters and officers should not assume that the situation is hopeless for trapped victims after the first day.
US&R operations should be scaled back only after all potential survivable void spaces have been inspected, even if it takes weeks. In this sense, the survival of trapped victims also becomes a function of planning, equipment, and training and experience of firefighters and other rescuers, who must locate, treat, and extract victims before they succumb to injury, dust inhalation, crush syndrome, dehydration, additional structural collapse during aftershocks, secondary explosions, or other complications.
Therefore, firefighters and officers should be taught and conditioned to avoid the natural temptation to declare an end to the “rescue” stage of operations until all potential survivable void spaces have been searched for live victims and the operations move to Stage 5.
Sometimes the strategy of void space searches (Stage 3) is alternated with selective debris removal (Stage 4) until the entire collapse zone is dismantled and all victims are located and extracted. These are high-risk operations, because the stability of the building was compromised by the original event and is often made far worse during Stage 4. This process should generally continue until the entire building has been dismantled and all possible survivors have been located and extracted. These operations are extremely dangerous because of the instability of damaged buildings as well as the continuing aftershocks that accompany major earthquakes. Without proper training, equipment, and experience, personnel conducting these operations can cause the building to collapse, killing rescuers and victims alike.
It is during these stages of a disaster that some of the most difficult, complex, and time-consuming rescues are made, the so-called miracles of disaster response. These operations are the “bread and butter” of modern US&R-ready fire departments as well as US&R teams from many nations, including the U.S. Federal Emergency Management Agency’s 28 US&R task forces. Until these phases of rescue have been completed, officials should refrain from declaring that the “recovery phase” has begun.
1. My unit was on the scene helping Los Angeles Fire Department personnel evaluating the structural stability of a nearby nursing home when the sinkhole collapsed, sending firefighters and police officers running as the street began to fall in. The water was swirling around and disappeared into the subway tunnels in seconds, setting off a rescue operation for firefighters and workers who had evacuated the tunnels just as the water was beginning to collapse the roof. They barely escaped with their lives.
LARRY COLLINS is a 27-year member of the Los Angeles County (CA) Fire Department (LACoFD); a captain; and a USAR specialist and paramedic assigned to USAR Task Force 103, which responds to technical rescues and multialarm fires across Los Angeles County. He is a search team manager for LACoFD’s FEMA/OFDA US&R Task Force for domestic and international response and serves as an US&R specialist on the “Red” FEMA US&R Incident Support Team (with deployments to the Oklahoma City bombing; the 9/11 Pentagon collapse; Hurricanes Frances, Ivan, Dennis, Katrina, Rita, and Wilma; and several national security events). He has had numerous articles published in Fire Engineering and is the author of Technical Rescue Operations Volumes I and II (Pennwell, 2004 and 2005, respectively) and the Rescue chapter of The Fire Chief’s Handbook.