TRENCH RESCUE LESSONS LEARNED

BY ADAM O’CONNOR

Ihear people say on occasion, “Have you ever had one of those days where everything goes wrong?” This statement is usually followed by a litany of coffee stain problems and Murphy’s Law grumblings. We have all had those days. Our job as firefighters is all about helping people when they are having their “worst day.” When everything goes wrong, it is our job to say, “Enough! The bad stuff stops here!” Okay, maybe it’s not that dramatic, but through training, experience, and determination, we try to deal with everyone’s worst day.


Photos 1-4, 6 by Bob Amber

Thankfully, not every day that starts disastrously ends that way. This is the story of a 21-year-old construction worker who was caught in a trench collapse and nearly lost his life. At some point he must have thought this was the worst day of his life; it might have been the last. Fortunately, it got better. This is a trench rescue story where everything went right.

SOMEBODY CALLED 911

On the morning of April 25, 2005, Huntertown (IN) Emergency Medical Services, just north of Fort Wayne, was dispatched on a medical run to a rural excavation site in its district. On arrival, the crew assessed the scene and requested the Fort Wayne (IN) Fire Department (FWFD) Technical Rescue Team to respond. Fort Wayne Communications dispatched the four members of Rescue 1 and three members of the Tech Rescue team. The remaining 10 Tech Rescue team members were also dispatched from engine companies all over the city. This is the standard deployment model for technical rescue, scuba, and haz-mat incidents in Fort Wayne.


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When Tech Rescue arrived on-scene, it found the victim in a 12-foot trench buried up to his chest. Several key things had already happened at this point. The excavator had been turned off, eliminating vibration and carbon monoxide in the trench. The initial EMS crew persuaded other construction workers to evacuate the trench. This was important-it allowed rescuers to go to work immediately. Another lucky break-there was no spoil pile on either side of the trench, which allowed rescuers access to both sides of the trench without needing to move any dirt.

On arrival, the Tech Rescue team immediately went to work. Members lined the edge of the trench with ground sheeting to distribute the weight of the rescuers and prevent further collapse. The team lowered treated 4 × 4 posts into the trench and slid arctic birch panels into position on them. These first two panels were then secured with an pneumatic shore (photos 1, 2).


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Once the first shore was in place, a rescuer was sent in to assess the patient. Another rescuer began to set the rest of the shores. The initial assessment in the trench revealed that the victim had suffered severe damage to his left arm and shoulder and had a bleeding head wound. EMS had lowered an oxygen mask to the victim as it waited for Tech Rescue. Later, a Tech Rescue team member, also a paramedic, entered the trench to monitor the victim and provide basic life support (photo 3).


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The Tech Rescue team began uncovering this victim using regular shovels; massive amounts of dirt had to be removed. As rescuers dug closer to the victim, they had to use small garden trowels, claw hammers, and their hands to remove the heavy clay soil. There was nothing fancy about the way the soil was removed from the trench. Rescuers used buckets tied to ropes to remove the soil. Propane-heated air was fed through a flexible ventilation pipe into the ditch to keep the victim warm and the air fresh (photo 4).

After an hour the victim’s right leg was freed. As rescuers started to remove the dirt around the victim’s left knee, they got an unpleasant surprise. Water began to squirt into the ditch. It immediately began to fill the area around the victim, which was the deepest point in the excavation. The Trench Group leader called for the dewatering pump as the Tech Team members in the ditch dug with even greater fervor (the dewatering pump used was essentially a 120-volt, 54-gpm sump pump inside of a perforated bucket).

The victim was close to being free, but the rescuers saw the situation worsening. In clearing the dirt away from the victim, the rescuers had actually dug below their panels. Rescuers began to fear that the water flowing into the excavation would cause the wall below the panel to slough and they would have to start over. The victim had been very brave to this point, but another hour of pain and possible hypothermia was not acceptable to anyone. It was time to go!

Rescuers were able to stand the victim, leaving just his left foot buried in the mud. One left foot doesn’t sound like much, but it was literally “stuck in the mud.” With a constricted area to work in, and an exhausted victim, rescuers still had a lot of digging to do. The water was still coming in.


photo 5 by Pat Feely.

This is when the victim decided he had had enough. After being buried for two hours in cold dirt, the victim began to work his own leg out of the mud. He pulled with all he had and allowed a rescuer to get a hand on his yellow rubber boot. Then, just when everyone was giving their all, and muscles were straining, and neck veins were bulging, his foot popped free! It came out of the mud, boot and all!


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Those at the scene all breathed a collective sigh of relief. The victim was quickly strapped to a backboard and put into a rescue basket. As the victim lay in the basket waiting to be lifted out of the trench, he began to shiver uncontrollably. The pain, hypothermia, and adrenaline of being trapped had finally taken their toll. He was soon out of the hole, and the rescuers watched as the victim was whisked away on the Samaritan helicopter (photos 5, 6).

LESSONS LEARNED

Fort Wayne Fire was assisted by the Huntertown Volunteer Fire Department, the South West Allen County Fire Department (SWACFD), and the Samaritan helicopter crew in successfully extricating this young man from a collapsed excavation and ending his “worst day.” When the dust had settled from the helicopter’s rotors, the Tech Rescue team had time to critique the incident.

Command. The incident command system (ICS) is designed for “all risk,” meaning it can be used on any emergency scene. It is also designed to be modular, meaning that the IC can compartmentalize as many facets of the situation as he needs to. On this scene, there were some easily recognizable modules. There was a battalion chief in command. In his span of control were EMS, a district chief of safety, and a district chief of operations. Under Operations was the Trench Group. FWFD has used ICS for decades. ICS is internalized from annual review and constantly reinforced at working fires. It is what we expect, and that pays dividends at unexpected situations.

The captain on Rescue One that day was also a long time Tech Rescue team member. He became leader of the Trench Group. This was very important throughout the rescue. On several occasions when things started to get out of control, he reminded everyone that he was in charge of the immediate operation. This meant nothing would be ordered in the trench unless it went through him. This was especially important when setting pneumatic shores, which operate under high pressure and could easily crush a misplaced finger.

The Tech Rescue members of FWFD train together regularly. From this training, an unofficial hierarchy has developed and we know who will be in command of the Trench Group depending on who is on the scene. It doesn’t matter whether it is from rank, experience, or personality-someone has to be in command of the trench.

Scene Safety. As mentioned before, the excavator was shut down when we arrived. Shutting down equipment is essential because of the vibration and carbon monoxide it will produce.

The other workers were out of the trench. This is important so that rescuers don’t waste their time trying to get able bodies to clear the trench when they could be helping the real victim. At this particular scene, the EMS unit that was originally dispatched had cleared the other workers from the trench. This took some serious persuasion on their part. Make no mistake; these workers had the best intentions, but when we arrive on the scene we need unfettered access to the victim. Drive home this point to anyone who will listen.

Staffing. The Tech Rescue truck was dispatched with Rescue 1 and Battalion 13, which picked up two more Tech Rescue members. These FWFD personnel, combined with Huntertown EMS and volunteers on the scene, provided us at least 10 rescuers on the original scene, all of which were needed. Eventually, there were more than 30 on-scene as the incident progressed and Tech Rescue and ancillary personnel arrived from FWFD and SWACFD. You can never have too many people on the original scene at a technical rescue.

Shoring the Trench. Rescuers immediately began to lay plywood ground sheeting around the trench. Ground sheeting disperses the weight of rescuers operating around the trench and helps prevent further collapse of the trench wall.

Shoring panels made of artic birch plywood and treated 2 × 12s were slid down treated 4 × 4s into the trench on either side of the victim. They were then held in place with ropes until our shores were in place. We lowered our shores into the trench with large aluminum hooks and inflated them from a portable air cart. This allows the first panel to be set without putting a rescuer into the trench.

As soon as the first two panels were set, we got a rescuer into the trench to assess the victim. As the assessment took place, a second rescuer was setting the next two panels. The setting of these panels went quickly and safely. There is only one reason for this-we practice setting shores in real trenches with horrible soil. We actually have a really nice concrete trench simulator, but we never use it because it is unrealistic. Challenge your team in training, and real scenarios will be less intimidating.

Unearthing the Victim. This victim was buried up to his chest, so we had a lot of dirt to remove. We started digging with shovels to remove as much dirt as possible. The victim tried to give us some idea where his legs were, but he wasn’t completely sure. After we cleared the first few feet of dirt from around the victim, we switched to using small spades, garden trowels, and sometimes our hands to finish the job. The goal is to unearth the victim quickly without causing him further injury.

We removed the dirt by filling buckets and having them pulled up with a rope. We learned two things about this system. The first is that you need two separate buckets and ropes for each digger so that he never has to stop. The other is that the rope should be tied directly to the bucket, not the handle. The handle on one of our buckets failed. If a team trains with manikins in real trenches, it will have a much better idea of how much time it takes to unearth a victim.

In many situations, a trench rescue could be augmented by the use of a vacuum or sewer cleaning truck. FWFD has an agreement with the Sewer Department to use its vacuum trucks if needed. The operations chief at this incident felt the noise and vibration caused by the vacuum truck would outweigh its effectiveness on the large pieces of heavy Indiana clay that had entrapped our victim. It is important to note, however, that these sewer trucks would be very useful in removing large amounts of water from an excavation. Other agencies have used these trucks with great success, and it is reported that they cut by 50 percent digging time in loose soil.

Personnel Management. There was a lot of talk at this scene about how much time a rescuer should spend working before being replaced. Every rescuer is different, and there is no way to put a time limit on this kind of work. It is not as if your air bottle runs out. If a rescuer is slowing down because of fatigue, replace him. If a rescuer is productive and appears to have a plan, let him continue. However, if someone needs a break, the trench is not the place to do it. If rescuers need to catch their breath or rehydrate themselves, replace them with fresh bodies. There is a time factor in trench rescue. Cold dirt, cold water, pain, and blood loss can lead to shock and hypothermia.

Extrication from the Trench. Once the victim was in the rescue basket, we faced the challenge of getting him out of the trench through the shores. We didn’t feel we had time or space to set whalers (i.e., horizontal lumber that spans several panels and eliminates the middle shoring). We decided to lift the victim from one level of shores to the next until we placed him on the top set of shores. Once the victim was above the top set of shores, he was pulled to the top of the panels. This was done by placing webbing on each corner of the rescue basket and pulling all of them at the same time. The victim was then grabbed by a sea of rescuer arms at the top of the panel.

After corresponding with experts in the field, we have reevaluated our approach to victim removal. In the future, we will train to incorporate an aerial ladder into the process. After the trench is shored, we will set and lock an aerial ladder over the trench, to be used as an anchor for a vertical haul system that will be used to raise the victim from the trench. Using an aerial device would work effectively with the spine immobilization and harness system we use in confined-space and high-angle rescue.

As with any running equipment, be very aware of the vibration and carbon monoxide produced.

EMS in the Trench. Make every attempt to keep the victim warm. We use a propane heater/fan unit and a long flexible pipe to pump warm air into the trench. We also have a paramedic on our Tech Rescue team, a real asset. He was able to assess and stabilize the victim in the trench and then help with digging. Being able to dig and monitor the victim at the same time became invaluable. Having to switch personnel in and out of the trench would have cost valuable time.

Cross-Training. In recent years, FWFD has trained with surrounding departments, especially in tech rescue and haz mat. It paid off at this scene. SWACFD Tech Rescue and the Huntertown Fire Department provided the needed equipment and motivated staffing at this scene. Just knowing what resources each had was helpful in getting personnel on the scene quickly.

We didn’t use the vacuum truck at this particular incident; but because of previous training with the Sewer Department, our operations chief was aware of its capabilities.

Wrap Up

The points below will help ensure a successful operation.

• Use the incident command system.

Get as much personnel to the scene as possible. You can always turn them around.

• Train in real trenches doing realistic scenarios.

• Have an established system for dirt removal.

• Monitor rescuers to make sure they are being productive. Replace them if necessary.

Have a plan for getting the victim out of the trench once he is freed.

• Coordinate and cross train with EMS and other departments.

• Adopt “Best Practices” from wherever you can find them. As a result of this incident, we are planning to incorporate the use of an aerial ladder into our victim removal strategy.

Take advantage of others’ experience and expertise. We are all in this “worst day” business together.

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