The release of a redacted copy of the Fire Department's investigative report comes less than a week after a five-alarm blaze in the city's nearby Bernal Heights burned several buildings. That incident was the latest in a series of Mission District fires that have prompted city officials to push for new safety measures and tighter inspections for the city's apartment buildings.
In the Rolling Stock fire, investigators were unable to isolate a cause but concluded the blaze was an accident, most likely started by some sort of electrical fault or discarded smoking materials.
The report chronicles some of the most dramatic moments of the fight against the fast-moving conflagration.
The first firefighters on the scene told investigators they could actually hear the fire moving when they entered the building.
An Engine 7 crew forced their way into the tire and wheel shop's locked front door. They tried to lead a small water hose line through the entrance into the customer service area but couldn't see anything as heavy black smoke swirled around them.
One firefighter told investigators he could hear the "roar" of the fire above him, the report said. His crew was then ordered out of the building.
After a rescue squad opened a garage door of the auto shop, firefighters saw fire advancing right above them and they were also ordered out of the structure.
The building's roof would collapse as firefighters battled the blaze from outside.
The fire caused extreme damage to the cars inside the shop. Investigators said the vehicles were damaged by heat, smoke, water and falling debris from the collapsed roof.
"The metal tire racks were affected by extreme heat causing deformity of the metal framing," wrote investigator Michael Horta.
All four tires on one vehicle were melted, their rims "extremely oxidized." The fire melted the vehicle's cargo exterior fiberglass cover, exposing its steel frame. The entire inside interior, dashboard and steering wheel were consumed by fire and the front seats were reduced to their steel frames as well.
The actual start of the fire may have been caught on videotape, but officials will never get to see the footage.
There were around 16 surveillance cameras inside the shop area and around the building. The arson task force asked the Police Department's crime scene investigation video unit to see if its members could retrieve video from the devices.
The police unit was unable to get the video to work, so they asked a data recovery company in Novato for help. But no luck. "We were informed that the DVR was beyond salvage and the data could not be retrieved," Horta wrote.
More than a week after the fire, investigators found discarded smoking materials and "stranded electrical wiring" in an area believed to be where the fire had started.
"We were unable to eliminate an unspecified electrical fault or failure as well as discarded smoking materials found at the scene as being involved in the ignition sequence of the fire," the report stated -- investigators' language for the likely cause, or causes, of the fire.