Structural Collapse at Dwelling Fire Results in Two Firefighter Fatalities - (Stockton, California - February 6, 1997) » Analysis

Structural Analysis

Analysis of the structure indicated that the heavy second floor was inadequately supported and vulnerable to the type of catastrophic collapse that occurred. The direct cause of the collapse was attributed to either a failure of the 4x6 support post within the room or the failure of the header beam itself.

It would have been difficult to anticipate the collapse that occurred without prior knowledge of the structure or a detailed size-up of the structure at the time of the fire. Large open ground floor areas with extensive wall openings are normally considered to have collapse potential. However, the potential for collapse in the building was difficult to ascertain due to the large volume of flames and the lack of accessibility to view the structural components.

Several firefighter fatalities have occurred in structures that presented significantly different appearances from different viewing positions, including several instances where interior crews were unaware of other floor levels either above or below them. The presence of differing construction ( i.e. wood frame addition to a brick structure) should also be an indicator of potential structural problems. Observations of this nature should be clearly communicated, to ensure that interior crews will be aware of structural features identified by exterior personnel. The arrangement of the structure, with a two-story addition at the rear of what appeared to be a single story dwelling, should have been a warning.

Accountability

The lack of crew integrity and accountability was an important factor at this incident. Instead of working as cohesive teams, crew members were separated and rearranged themselves to perform different tasks and functions as the circumstances unfolded. Company officers were often unaware of the location and function of their respective crew members and several personnel working inside the structure were unsupervised and not in radio contact with the Incident Commander at different times. The lack of communication became critical when the collapse occurred and no one knew who was in the area or who was missing.

After the collapse occurred, several attempts were made to account for all of the personnel on the scene and determine who was missing. The first request for an accountability check came from Battalion 1, seconds after the collapse occurred, however a full accounting for personnel was not accomplished until the last victim had been removed, more than an hour and a half later. Two of the three victims who were removed had not been reported as missing.

The first attempt at an accountability check was assigned to a firefighter a few minutes after the collapse occurred. He attempted a face-to-face check of all crews on the scene, however this was unsuccessful due to the confusion and constant movement of personnel as they attempted to rescue the trapped victims.

At 4:55 a.m. an off-duty chief’s operator arrived at the command post and took over the accountability process, attempting a roll-call of the units by radio. This was also unsuccessful due to the number of interruptions caused by urgent messages on the tactical radio channel and the difficulty of contacting company officers who were engaged in the unfolding rescue operation.

Incident Management

The first arriving company officer (E9 Captain) gave a report on visible fire conditions and called for a second alarm, but did not provide any further direction for incoming units. Incident command was established when the battalion chief arrived. However, most of the tactical functions performed by individual companies appeared to have been self-initiated and uncoordinated. The existence and condition of the second floor addition was not initially recognized or clearly communicated to the interior crews. While the volume of the fire was significant, it did not initially appear to be unusually dangerous or challenging and there was no recognition that the incident involved unusual structural hazards.

During the initial attack stage, the Incident Commander (Bat 2) was located near the front of the fire building, while a remote command post was staffed by the chief’s operator. Most of the radio traffic, including several assignments to incoming units, was handled by the operator, who was not physically located with the Incident Commander. The operator also relayed messages between Battalion Chief 1 who was outside at the rear and the Incident Commander (Bat 2) at the front of the building. The use of the operator to relay information appears to have contributed to the overall confusion and a lack of coordination among units, particularly when the units at the rear were reporting fire conditions that could not be observed by the Incident Commander at the front of the building.

The Incident Commander attempted to size-up the situation from the exterior and his major concern appeared to be exterior exposures, although there was an interior attack in progress with a report of a trapped occupant. The extra company that was dispatched to provide a rapid intervention team was reassigned to cover an exposure and the RIT assignment was not covered for several minutes. No safety officer was assigned until after the collapse occurred.

The Incident Commander did not receive reports on interior conditions from the crews working inside the house and apparently did not provide direction to them. As the threat of extension to the exposure was controlled, the authorization was given to hit the fire on the second floor through the windows, however the interior crews were not specifically warned. While this action did not appear to have caused the collapse, the notification would have made the interior crews aware of the upper floor and the associated risk. The radio transcript suggests that the Incident Commander did not realize that the interior crews had worked their way into the rear portion of the structure.

The incident management structure expanded when the off-duty command officers arrived at the command post as a result of the second alarm. The absence of support units that would normally deploy to an incident such as this and sufficient radios to ensure that all officers were able to communicate minimized the effectiveness of these additional resources.

Protective Clothing and Equipment

The protective clothing, SCBAs, PASS devices and radios assigned to the trapped firefighters and Captain were tested and determined to be functional. The deaths and injuries do not appear to be related to any failure to use protective equipment or any shortcomings of the equipment itself. However, there were no reports that PASS devices could be heard or the alarming units were helpful in locating the trapped individuals, suggesting that their PASS devices may not been activated.

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