A fatal blaze at a downtown Coos Bay auto parts store on Monday began when flue heat ignited wooden beams and trapped a fire in concealed spaces between the ceiling and roof of the boxy structure.
State Fire Marshal Robert Garrison said Wednesday that grease being incinerated in a furnace at a parts-cleaning operation at the Farwest Truck & Auto Supply store caused the combustion of roofing materials that burst into flames when they came in contact with a supply of oxygen.
"That fire probably burned for many hours without being detected," Garrison said. "Consequently, it had done extensive damage to the construction of the building, especially the roof, without being seen."
Once the blaze began in earnest, aerosol cans, paints, hydraulic fluid, paint thinners and motor oils stored at the auto supply accelerated the massive blaze that sent caustic black plumes shooting hundreds of feet into the air. Explosions burst in pops of flames and burned so hot temperature increases could be felt 50 feet away.
Two volunteers and a career firefighter with the Coos Bay Fire Department were killed when a roof collapsed and trapped the men inside while they were fighting the blaze.
Robert "Chuck" Hanners, 33, a Coos Bay resident, died at Bay Area Hospital after being found near a stairway and taken from the fire. A volunteer with eight years of experience, Hanners never regained consciousness after being dragged from the blaze. Randall "Randy" Carpenter, 46, a Coos Bay resident and a career firefighter for 15 years, died inside the building. Jeffery "Jeff" E. Common, 30, a Coos Bay resident and volunteer for 12 years at Coos Bay and North Bend, also died inside the burning building.
On the day of the blaze, owner Kim Macfee said he believed the fire began on the mezzanine level of the store and the fire marshal's report appears to corroborate his suspicions.
"It started next to a stove in the back, up in the ceiling," Macfee said on Monday, when he took a break from agitatedly running before his burning building.
Macfee said thickening smoke in the store had concerned him and after calling the fire department and grabbing important data, he, about eight employees and several customers walked out of the store and waited for the fire department to arrive. None was injured.
Firefighters responding to a general alarm at 340 S. Second St. found only light, yellow-brown smoke wafting around the building, indicating at the time an average fire that hid the ferocity with which the blaze would progress.
"It presented itself as a very small fire without much smoke showing because the fire was being contained," Garrison said. "There was heavy damage done to the roof before firefighters ever arrived."
Initial reports following the blaze indicated that a response inside the building included two teams of firefighters inside the structure and a third group on a rooftop that became spongy and malleable from the searing heat.
Unable to find the source of the fire and feeling the increasing temperature, firefighters on the inside became concerned that the blaze was burning in a dead zone between the roof and the top floor ceiling.
"You have wood framing exposed to extensive heat and combustibles and eventually you have a fire," Garrison said. "It's as simple as that."
Fire Chief Stan Gibson provided initial speculation that when firefighters tried to carve an opening in the building's ceiling, trapped gases found the oxygen they needed to flash into a blaze. The ceiling, floors and walls combusted immediately and possibly caused a rafter to dislodge and cave in on the men.
Evacuation orders had been issued. However it remains unclear why the three men did not leave. Garrison said that part of the investigation has not yet been addressed.
A secondary investigation into the fire is being conducted by the Oregon Occupational Safety and Hazards Administration, a standard any time firefighter fatalities are involved in a case. Findings from that investigation are not expected to be reported several for months.