At 09:18 hours on March 1, 2011 we responded to a fire in an older Victorian residence with balloon construction. The fire was contained to a laundry room, and was burning inside the wall when crews arrived. The fire attack captain advised me that there was no visible fire in the room, and they discovered the fire as they began to remove the drywall. The laundry room was empty and there was gas and electric service to the house. Crews had shut off the gas and electricity shortly after arriving on scene. The only utility in the area affected by the fire was a gas line. The origin of the fire was near the elbow on the gas line near the shut off valve for the dryer, this was evident due to complete destruction of some wood members in the area and deep charring. There was an additional area of deep char near an elbow at the top end of the gas line, this was possibly and additional point of origin. We were unable to locate any obvious cause of ignition in the area of the fire, or the debris that was removed prior to the investigator’s arrival. We requested the gas and electric companies to respond and assist with the evaluation of the utilities at the residence. The gas company detected a small leak in the system and placed a plug in the meter. They did no test to see if the leak was on the gas pipe in the area of origin prior to plugging the meter. The house had an old knob and tube wiring system and was serviced by an electrical panel with knife switches and screw in fuses. There was Romex wiring added to this system, and there was no apparent ground according to the electric company. Under our direction the electric company energized the system to determine if there was electricity in the gas line. The electric company found there were approx. 25-50 volts at the gas meter, and 100-130 volts at the gas pipe in the area of origin. Based on this information the electric company disconnected the electric service at the pole until the electrical issue can be resolved. We contacted the property owner to inform him of the electrical issues, and informed Building & Safety of the issues at the residence.
Fortunately no one was injured at this incident; however the potential for electric shock or electrocution existed at the gas meter and the gas pipe in the area of origin. The captain who shut off the gas used a plastic utility wrench that he carried in his turnouts, this possibly prevented an electric shock or electrocution. The electric panel was in the laundry room, and the knife switches caused an additional hazard to responding personnel.
