Calumet Water Reclamation Plant Explosion and Building Collapse: Lessons Learned

Chicago firefighters respond to explosion and collapse

At approximately 11:00 a.m. on August 30, 2018, the Chicago (IL) Fire Department (CFD) was dispatched to an explosion and a building collapse with trapped occupants on the far southeast side of the city. The standard response for this run within the city is a still and box alarm with additional companies from the Special Operations Division.

Initial Response

The initial response included four engines, two trucks, one tower ladder, three battalion chiefs, one deputy district chief, one additional truck for the rapid intervention team (RIT) and an additional battalion chief for RIT, three ambulances, and one emergency medical services (EMS) chief. The Special Operations companies included two heavy rescue companies, Squads 1 and 5; Building Collapse units 5-2-1 and 5-2-2; Battalion Chief 5-1-5; Special Operations 5-1-9; Special Operations Safety; and Chief of Special Operations 2-1-28.

An overview of the structural collapse after the explosion.
An overview of the structural collapse after the explosion.

(1-2) An overview of the structural collapse after the explosion. (Photos by Gordon J. Nord Jr. unless otherwise noted.)

Arrival of First Chief Officer

On arrival of Battalion 22, the first-arriving chief officer alerted the Englewood Fire Alarm Office that he had a bona fide incident with trapped civilians. He immediately asked for an EMS Plan 2, which added seven advanced life support (ALS) ambulances and a level 1 hazardous materials response, because of the smell of gas.

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His continued size-up included this description: “Office, I have a one-story fire resistive approximately 100 × 70 pancake collapse with multiple trapped. I’m working on a full accounting of the missing.”

The Structure

The building in question underwent several additions and enclosures from 1975 through 2009, according to a report from Wiss, Janney, Elstner Associates, Inc., the engineering firm that investigated the explosion and collapse. The report determined that the explosion originated in the gravity belt thickener (GBT) room. The GBT room walls were cast in place with reinforced concrete frame with brick masonry and concrete infill. The roof structure consisted of precast prestressed concrete single T-beams spanning 110 feet between the east and west exterior walls.

The floor of the room served as a roof over three below-grade tanks that collected wastewater sludge. This floor structure consisted of cast-in-place reinforced concrete beams with integral 12-inch-thick slab sections. In six areas over the east and center tanks, depressed slabs with a tapered cross-section and sloped top surface were separately cast between reinforced concrete beams at the perimeter of the area. The construction of this part of the building made the rescue operation quite intricate.

The primary rescue access from which the last victim was rescued.

(3) The primary rescue access from which the last victim was rescued.

Rescue of Worker

On arrival of the chief of Special Operations (2-1-28), the second-arriving chief officer, Battalion 22 transferred command and gave a status report. Eight of 10 workers inside the building had been removed. An additional worker, on side A, or the west, was found, but he was trapped. An additional civilian was still missing.

Firefighters on the scene were performing a hasty surface search of the entire building. Truck 27 and Squad 5 were obtaining cribbing and hydraulic rescue tools to rescue the one civilian on side A of the building. The incident commander (IC) went inside for face-to-face communication with the Rescue Squad 5 officer to ascertain the progress of the rescue. The Squad 5 and Truck 27 lieutenants assured Command that the lifting operation to rescue this civilian would be short and successful. After lifting some assorted debris by using two hydraulic lifting tools in tandem with cribbing, the victim was freed and removed. The operation was completed within 10 minutes.

Search for Missing Worker

We, the two chief officers on scene, asked for the plant manager so we could speak with someone from the work crew who was ambulatory to ascertain the point at which the missing worker was seen last. We were quickly brought to the rear of the structure where we hailed loudly for the last trapped civilian. He answered on the second call.

Collapse technicians from the heavy rescue companies crawled into the debris field about 40 feet. They found him within two minutes, but the civilian was heavily trapped. All the members of Squads 1 and 5 were summoned to the rear of the structure to survey the area by hand and create a rescue plan.

At this time, the chief of operations (2-1-5) arrived on the scene and took overall command. He requested a 2-11 alarm, which put more than 42 companies and more than 100 members operating as one team. Twenty-five of those members made up the rescue sector working under Special Operations Command.

The east end of the single T-beam that fell from the roof.

(4) The east end of the single T-beam that fell from the roof. (Photo courtesy of Wiss, Janney, Elstner Associates, Inc.)

Students in the 56-hour Illinois Fire Service Institute Structural Collapse Rescue Technician course performing a bridge beam lift with a trapped vehicle underneath, the lift used to rescue the worker in this incident.

(5) Students in the 56-hour Illinois Fire Service Institute Structural Collapse Rescue Technician course performing a bridge beam lift with a trapped vehicle underneath, the lift used to rescue the worker in this incident. (Photo courtesy of the Illinois Fire Service Institute.)

Primary Rescue Point

The initial survey team consisted of four collapse technicians, who were supervised by two lieutenants, one from Squad 1 and the other from Squad 5, who are trained in collapse; the crew consisted of six members.

Immediately on entering the structure from the rear manway door, four gas monitors sounded their alarms for 10 percent lower explosive level (LEL) of flammable gas. Rescue Command ordered that the glass block windows be removed from the entire structure to provide a cross breeze. Forced ventilation with bag air was brought to the side of the trapped victim. Rescuers who had begun a tunneling operation to reach the victim carried four gas monitors and standalone pass alarms.

Squads 1 and 5 split their crews into two companies. One company tunneled, and the other shored concrete elements and provided cribbing and shores to the tunneling crews. Battalion Chief 5-1-5 took command of the tunneling operation and Battalion Chief 22 of shoring and logistics. As the chief of Special Operations, I was in charge of the overall rescue command.

The Hazardous Materials sector monitored and provided forced ventilation at several points throughout the structure to ensure proper air for all rescuers and the victim. Multiple linked unmanned hazmat monitors, along with handheld and personal monitors, were used extensively in this operation to ensure good air quality.

Squads 1 and 5 survey teams determined, after tunneling as closely as possible to the victim from 360˚, that coming in from the debris pile from the east and tunneling down to the victim under the protection of the 110-foot T-beam that appeared to be resting on the ground would be the safest and fastest way to reach the victim. One rescuer remained on top of the debris pile to communicate with the victim for the duration of the incident.

Shoring teams from the squads and collapse companies immediately began to place struts on the T-beam. Rescuers paralleled the beam while tunneling to provide lateral and vertical support and direct contact with the floor below to ensure capture so that good load transfer could be visually confirmed. They also shored T-beams to the north and south of the beam near which rescuers were working.

Since it was quite evident that we would need more lumber than was carried on the lumber truck, we requested additional lumber from the Special Operations Warehouse. A request was made also for a compressor, Concrete Demolition Unit 5-2-4, a crane, a structural engineer, and plant schematics.

According to the forensic report issued by Wiss, Janney, Elstner Associates, Inc. for the Metropolitan Water Reclamation District, each of the eight precast prestressed single roof T-beams over the GBT room collapsed. Portions of the collapsed beam’s metal flanges had broken off the roof beams. Each of the beams broke into three sections anywhere from 32 to 48 feet long. These observations were made during a forensic demolition of the building after the incident.

It was clear to the first rescuer who reached the trapped civilian that we had a big problem. The firefighter/paramedic from Squad 5 who reached the entombed victim stated the victim was pinned under a T-beam two feet away from the top opening of a sludge tank with a vertical drop of about 20 feet. During the rescue, we could see the total length of the roof-supporting T-beams, but we could not tell if they were fractured.

On reaching the victim, the member of Squad 5 made an initial assessment and began treating the victim. He started an IV as a treatment for a crush injury and established medical control with the University of Chicago. The rescue team lifted the beam using air bags and two crib towers to capture the load. All of the mechanical systems that had been on the ceiling were on top of the victim just below the T-beam. Heating, ventilation, and air-conditioning; electrical; and lighting fixtures had to be removed one piece at a time to create an opening large enough to slide the victim from under the beam to the north into an open, safe area.

Crews work on cutting additional cribbing for rescue efforts.

(6) Crews work on cutting additional cribbing for rescue efforts.

Crews remove the last trapped ironworker to the waiting University of Chicago Aeromedical Network Helicopter.

(7) Crews remove the last trapped ironworker to the waiting University of Chicago Aeromedical Network Helicopter.

The CFD was lucky that a good majority of the members working within the collapse zone were instructors for the Illinois Fire Service Institute (IFSI) Structural Collapse Rescue Program. One of the team-building evolutions during the 56-hour Structural Collapse Rescue Technician course is a bridge beam lift with a trapped vehicle underneath. This evolution represents the rescues made during the Loma Prieta Earthquake on October 17, 1989. The evolution consists of two five-person teams lifting the 80-foot bridge beam off a late-model sedan with trapped occupants inside. The beam is placed delicately on the auto in a twisted unsupported way so that the lift is performed slowly under the watchful eye of the IFSI collapse instructional team.

Four crib towers are constructed below the beam, two for lifting and two for capturing the load. Small incremental lifts are performed to raise the beam about one foot, allowing rescuers to enter the car and free trapped victims. Two stacked air bags at each end are used to raise the beam and then lower it again. This exercise can take hours and is fully supported with guidance from IFSI instructors. Because of this elite technical rescue training, the Rescue sector officers at the water reclamation building collapse determined this would be the rescue plan enacted to free the trapped civilian.

Rescue team members had removed debris in and around the area of the victim. The company officers began the lifting evolution on the footprint to construct with cribbing a single lift tower and two capture towers. There was only enough room near the victim to have one lifting tower, and not all portions of the collapse were readily visible to perform two lifting stations. The Rescue sector officers felt that only an eight-inch lift was needed near the victim’s legs to successfully remove him. Once we were ready to lift, the University of Chicago Aeromedical Network (UCAN) was called to the scene to assist with medical stabilization of the victim and to provide quick transport back to the hospital’s Level 1 Trauma Center. Prior to removing the patient, there had been concern that one or both of the victim’s legs would have to be amputated or that the victim would decompensate once the T-beam was raised. The UCAN staffing included an emergency room trauma-trained physician and a registered nurse; they provided the next level of care beyond what the CFD could.

The lift went off without issue. The beam was raised eight times, and cribbing was put in place to capture the load. The collapse technician-trained firefighter/paramedic from Squad 5 crawled under the beam into a safe area and continued packaging and treating the victim. The victim was conscious but confused; both legs were intact but were badly broken.

The Rescue sector transferred care to the Medical sector once the victim was extricated from the pile. The victim was immediately flown to the University of Chicago Level 1 Trauma Center for treatment. The incident and scene were secured and struck out after four hours. The entire rescue was covered on live news across the city.

After many surgeries and months of rehabilitation, the victim was reunited with his rescuers at the quarters of Squad Company 1 for a morning brunch. The gentleman walked in under his own power, hugged each member of the team, and sat for several hours reliving that day.

This incident was impactful for all the right reasons but especially because it was a rescue, not a recovery. It was truly a “we” effort, and the rescuers executed the operation flawlessly. The biggest takeaway from the response was the value of training on large-scale technical rescue incidents. The companies responding to the water reclamation plant were successful because they had prepared. They continued their technical rescue training beyond operations-level education—most importantly, they prepared in an environment that simulated real-world rescues.

Lessons Learned

The following are lessons learned from this incident:

  • Training must simulate real-world rescues based on case studies.
  • Specialized crews across the city and region must train together continually.
  • Continuing education must be provided for all disciplines.
  • New tools and techniques must be introduced and tested.
  • On-site subject matter experts should be consulted (Trades).
  • Rescue must be coordinated with the Medical sector.
  • All rescue members, including Command, must be trained to the level of the incident.
  • A team approach with deliberate discussion is the key to success.
  • It is important to recognize the severity of the response early and to upgrade the alarm to support all positions. It took 100 rescuers to support one victim. Early resource recognition is critical for successful rescues, especially those that involve multiple trapped victims.
  • Teaching newer members is a great way to stay in touch with the ever-changing disciplines.

These lessons all come back to one key point: You cannot overlook the value of shared, common training for members who respond to large-scale incidents and departments that support mutual aid. Operational objectives need to be discussed and trained on for successful rescues.


TIMOTHY WALSH retired as chief of special operations from the Chicago (IL) Fire Department after 33 years of service. He has been a field staff instructor with the University of Illinois Fire Service Institute for the past 17 years, specializing in building collapse, rapid intervention team under fire, and command and company officer fireground command school. He has a master’s degree in fire and emergency management from Oklahoma State University and multiple certifications in rescue from the Illinois State Fire Marshal’s Office.

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