Interior Operations: “The Pit”
BY JIM HONE
I arrived in Oklahoma City as part of FEMA`s USAR Incident Support Team (IST). A plan of action was developed jointly to integrate the task forces into the search and rescue efforts of the Oklahoma City (OK) Fire Department (OCFD) and assisting agencies.
I was assigned to the interior operations chief position in the Murrah Building and was responsible for accomplishing the operational objectives inside the building. All tactical assignments would be accomplished through the combined efforts and coordination of the OCFD, local mutual-aid resources, FEMA USAR Task Forces, FBI, military, and contractors. This assignment was shared with Captain Mike Parrish from the Riverside (CA) Fire Department, who arrived the evening of April 20. I worked the day operational period from 0700-1900 hours, and Parrish worked the evening operational period from 1900-0700 hours.
INITIAL INTERIOR ASSIGNMENTS
The following initial interior assignments had to be accomplished simultaneously:
a thorough secondary search of the remaining areas of the second floor, occupied by America`s Kids Day-Care Center, and of the first floor where portions of the second and third floors had collapsed between Columns E22-18 and F22-18;
construction of emergency shoring systems in several areas where structural stability had been compromised;
significant debris removal from the first and second floors; and
removal of overhead hazards and debris from the edge of upper floors on the building`s north perimeter.
CHALLENGES
Search. The western aspect of the first and second floors required minimal debris removal, and search operations were accomplished quickly using a combination of USAR trained canines, electronic visual and listening devices, and physical search procedures.
The eastern aspect of the first and second floors near Columns 18 through 22 was not as easy. This area became known as “the Pit” because of the shape of the debris pile and the remaining portions of the building forming its perimeter.
The eastern edge was high-piled debris formed by the pancake collapse of nine floors between Columns 22 and 26, F to E (“the Bowl”). Rubble and office contents were packed tightly between the concrete floor panels and support beams. In one area, seven floors could be counted in a space less than 20 feet high.
The northern edge was formed by large pieces of concrete rubble and floor panels that had collapsed in a lean-to pattern. This area had the greatest potential for containing large void spaces and possible live victims inside the building. Local resources previously had conducted search and rescue operations, discovering and marking the locations of several deceased victims in the debris pile along the northern edge.
The southern edge was the front of the building and the original entrance. USAR canines easily searched through most of the debris in this area, but a significant amount of rubble had to be removed to provide a safer, more reliable route of access and egress.
Shoring. Several areas inside the building needed emergency shoring to prevent further building collapse and debris movement. The more significant areas inside the building requiring emergency shoring were south of Columns 16 and 18 under floors two and three. The primary concrete support beams had been fractured and separated from the columns. The northern edge of the second floor was five feet below its connection point on the column, and the third floor was two feet lower. A combination of timber and pipe vertical shoring systems was used. The large amount of lumber used in these shoring systems led this area to be called “the Forest.” Multiple combinations of box cribbing and raker shoring systems were needed in several locations to prevent movement of debris piles and damaged structural elements. Firefighter John O`Connell from the City of New York (NY) Fire Department Rescue Company 3 provided valuable technical assistance during the construction of several shoring systems.
The second- and third-floor support beams and panels south of Columns 20 and 22 had totally collapsed onto the first floor. This left the columns unsupported for nearly 40 feet in all directions. The lean-to pattern of debris inside the building was pushing north against the columns, and the lean-to pattern of debris outside was pushing south. This formed a “Christmas tree” pattern around the columns, which provided some limited stability.
Before any large pieces of debris could be moved, the columns had to be shored to prevent buckling. To prevent the columns from coming south, four- and six-inch pipe horizontal shoring systems 35 feet long were hand-carried into position and secured against suitable structural elements near the front of the building. To prevent the columns from moving in an east/west direction, shorter pipe shores were attached between the columns. To prevent movement north, one-inch steel cables were secured around the columns and tensioned in a southern direction toward the front of the building. IST Structures Specialist David Hammond and civilian contractors designed and fabricated these shoring systems.
Debris removal. To conduct effective search and shoring operations, personnel had to remove several thousand tons of debris from inside the building. The debris contained large and small pieces of concrete, HVAC components, computer cabling, office furniture, and other building contents. In addition to the normal debris associated with a structural collapse, also in the rubble were items associated with the tenants of the Murrah Building–large sums of money and legal tender documents from the credit union, sensitive files, automatic weapons and ammunition, and some victims` personal effects. An area was designated for the placement of such items, and FBI personnel came by regularly to remove them to an FBI evidence tent. At times, FBI agents joined a debris-removal team to assist in the collection of some of the more unique items.
During the first three days, more than 100 tons of debris were removed every 12-hour operational period by hand crews, buckets, and wheelbarrows. The rubble was carried from the Pit up ladders and deposited onto a plywood debris chute that ran to the bottom of the stairwell on the first floor. Tinker AFB Bobcats® then took it to an area designated by the FBI on the east side of the building, where it was raked and sifted.
The larger portions of columns and support beams were broken into smaller one- and two-ton pieces with pneumatic jackhammers and pavement breakers mounted on the fronts of the Bobcats. The one-inch rebar was cut with rotary saws or torches and dragged out to the debris collection area by the Bobcats. Several nonbearing interior cinder block walls were removed for the Bobcats to gain access from multiple directions to greatly speed up the debris-removal process.
Removing overhead hazards. This probably was the most visually dramatic problem and also one of the best indicators that the rescue process was in progress. Most of the overhead hazards were on the north face of the building and visible to the other rescuers, the public, and the media. The first overhead hazards rescue teams removed were the smaller pieces of rubble and office contents hanging over or next to the north end of the building. High winds and ground motion caused by heavy equipment moving in front of the building caused smaller but still deadly pieces of debris to continually fall onto rescuers working below. Rescuer fall protection with ropes and harnesses was critical during the operation. Numerous floor panels were broken, and the lower grid of 12-inch rebar was ripped away in several areas where portions of the floor had collapsed to the ground. Rescuers quickly provided a four-foot minimum clear zone around the north perimeter on floors three through nine. Several file cabinets resting on severely angled and hanging floor panels were removed by lowering rescuers onto the floor panels and having them place the file cabinets in debris sleds suspended by cranes.
The larger pieces of hanging roof and floor panels were either cut away and placed in large debris sleds suspended by cranes or attached directly to the crane cable and lowered to the ground or else secured to the building in a “tie-back” operation. Rescuers were lowered onto the hanging slabs where they would core drill, lace cables, and make connections to the crane or building. Most of this operation was coordinated by the exterior operations chiefs because they could observe and direct the operation better from their vantage point. Removing the larger overhead hazards and pieces of rubble from the debris pile in front of the building required close coordination with interior operations. At times, portions of interior operations were stopped during the removal of a large piece, which could fall or shift the debris pile near rescue workers inside the building.
These interior operational objectives continued in some form for 12 days. Daytime OCFD Rescue Operations Chief Mike Shannon, IST Operations Chief Ray Downey from the City of New York (NY) Fire Department, and Charles Smith from the Disaster Mortuary Team (D-MORT) combined information gathered during the incident and developed daily and extended operational objectives. As the incident progressed, it became obvious that most of the victims would be found inside the building along the northeastern edge of the Pit and on the exterior, east of the Pit perimeter, an area known as the Bowl. Because of the increased possibility of shifting debris piles, all interior operations were ceased on the 12th day. The rescue efforts continued with all operations conducted on the outside of the building.
LESSONS LEARNED AND REINFORCED
Few, if any, organizations have enough resources immediately available to effectively respond to an incident of this magnitude. The ability to quickly establish an incident management structure to provide for effective communication and coordination of multidisciplined resources is key to success.
You will perform as you practice. Organizations that spend the time and money to provide their members with effective equipment and props for realistic and recurring training will perform better and are safer than those that don`t.
Monitor and check the stability of emergency shoring systems during the entire rescue operation. Removing large amounts of debris will continually change the load and force angles on the shoring systems.
Rescuers will create their own trip hazards. Tools no longer in use and extra supplies have a tendency to be placed in access/egress pathways–the closest open areas. Watch for this to happen again and again during extended structural collapse incidents.
What looks bad is not always a hazard that needs immediate mitigation. Knowledge of structures, the capabilities of building components, and how they react in collapse situations is crucial to effective search and rescue operations. Some of the more deadly hazards are subtle and only identifiable when specifically looked for. Book knowledge must be enhanced with real-world, hands-on experience.
Effective communication is always one of the first “victims” in large-scale disasters. Ensure that all people you supervise know and understand the operational objectives and the priority of tactical assignments.
It is important for rescuers to complete mission assignments. It may be necessary to break up larger operational objectives into smaller tasks to ensure completion and the satisfaction of accomplishment.
Murphy`s Law will always be operating at your incidents. If it can go wrong, fall, or break, it will. Prepare for Murphy`s Law with preidentified, equipped, and staged contingency plans. n
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An area of the first and second floors collapsed in the rear of the Murrah Building, forming “the Pit.” This area required substantial horizontal bracing for stability. Here, cutting and debris slide operations are ongoing. The Pit yielded numerous victims.
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(Top) Breaking concrete in “the Pit.” (Bottom) Shoring operations at the edge of the collapse.
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The Pit was searched completely and every piece of debris was removed. This was facilitated when a minipayloader was brought in.
JIM HONE, a division chief with the Santa Monica (CA) Fire Department, is currently in charge of the Support Services Division, which is responsible for city disaster preparedness, public fire safety education, and fire communications. During his more than 21 years in the fire service, he has served as training officer, hazardous-materials coordinator, fire suppression captain, firefighter paramedic, and aircraft crash rescue specialist. He serves on several local, state, and federal disaster response teams and committees. He was an interior operations chief at the Oklahoma City Bombing.
