Summary

Restaurant Fire, Boston, Massachusetts
August 31, 1995

NFPA Report by Ed Comeau

Summary

A fire occurred in a restaurant located on the ground floor of a five story building. The fire originated in the grill area of the restaurant and extended through the exhaust ductwork to a mechanical room on the fifth floor. At this point, a flexible duct connector failed when exposed to the fire and the fire then spread out of the ductwork into the unsprinklered mechanical room. The wooden structural members and roof structure then became ignited, resulting in extensive damage to the roof.

Fire suppression operations were initially directed at gaining access to the void spaces under the roof and suppressing the fire. However, due to the height of the ceiling and the fact that there were double cocklofts, the decision was to mount a defensive fire fighting operation.

According to investigators from the Boston Fire Department, the fire was caused when cleaners were attempting to remove the grease buildup on a stove's cooking surface by placing layers of aluminum foil over the burners and then turning the burners on "high."

A fire ensued and spread into the ductwork above the grill.

The kitchen hood system was equipped with a wet chemical system that did not automatically operate. The Boston Fire Department determined that the conduit housing the cable that connects the fusible links had a significant buildup of grease that prevented the cable from moving once the links fused.

No attempts were made to manually suppress the fire or manually activate the wet chemical system. The slate roof structure of the historic building was destroyed, and all five floors of the building, including a bookstore on four of the floors, received significant water damage from the defensive fire fighting operations.

There were several significant contributing factors that led to the extension of the fire from the ductwork to the building:

• There was a flexible duct connector between the fan and the ductwork in a mechanical room on the fifth floor. This connector was not rated for this type of occupancy and failed at some point, allowing the fire to spread from beyond the ductwork into the mechanical room.
• The mechanical room was not sprinklered, which allowed the fire to spread from beyond this area to the underside of the roof structure.
• The cockloft area underneath the roof structure was not sprinklered, which allowed the fire to spread even further.
• According to the Boston Fire Department, the wet chemical system did not discharge during the incident, either automatically or manually.
• When the system was discharged by the fire department during its investigation, agent did not discharge out of several of the nozzles, indicating that they were plugged and inoperable.