A fire in the yet-to-be opened Central Subway in San Francisco has triggered a safety investigation by state regulators and could threaten the already-delayed opening date for the new Muni line until next year, NBC Bay Area’s Investigative Unit has learned.
The June 20th fire began in an electrical cabinet in the traction power room at the Yerba Buena/Moscone station, one of three in the subway extension to Chinatown. A Muni surveillance video, obtained by NBC Bay Area under the city’s Sunshine Ordinance and the state Public Records Act, shows that at 8:23 that night, there was a flash as red hot material was ejected from the back of the cabinet, which houses critical electrical equipment.
Then a stream of smoke slowly fills the power room. Two minutes later, a second flash on the video sends flames shooting as much as six feet above the cabinet, accompanied by still more sparks, sending much thicker smoke into the room. The video shows that just a minute later, another flareup occurred, causing molten material to be ejected out of the cabinet.
San Francisco fire crews responded when an automatic alarm sounded, but a Muni review of the fire obtained by NBC Bay Area indicated they weren’t able to get through the metallic roll-up front door, because they didn’t have keys.
The dispatch recording that night records how crews asked for help from the transit agency. “We need Muni down here,” one fire official told the dispatcher.
“Message received,” the dispatcher replied.
In the end, crews were able to get into the subway through an emergency exit.
By that time, the video shows, the smoke was so thick that fire crews needed flashlights to find their way around, even though the lights were still on in the room. Because the cabinet was still energized, crews couldn’t use water because of the risk of electrocution. They called in to dispatch for a carbon dioxide-equipped unit, which is deployed to smother electrical fires with foam.
While the first responding crews waited, the video shows the fire continued to burn.
In the end, despite all the obstacles and problems, crews managed to extinguish the fire before it got out of hand and nobody was injured.
But in light of the apparent safety issues, regulators with the California Public Utilities Commission opened a probe, CPUC officials say.
Separately, a San Francisco fire official submitted a report to the National Fire Incident Reporting System, documenting that the subway’s fire suppression system and emergency ventilation fans did not activate that night.
In an internal assessment of the June 20 incident, one Muni safety official indicated the contractor shut off the fire suppression system “based on the cost” of an “accidental discharge” -- estimated to be $42,000.
The memo then quoted one fire official as responding: “that means you are saying that one of our guys….is not worth $42,000,” citing it as an example of how limiting costs in some cases “can lead to poor decision-making related to safety issues.”
“Somebody could have been killed -- they just were lucky this time,” said Ken Buske, a veteran electrical engineer and forensic expert who has investigated more than 1,000 fires and reviewed the Muni findings.
He says the idled fire suppression system was a major red flag. “The Fire Department is walking into a situation where things are not as they should be,’’ Buske said, “which then risks the lives of firefighters.”
The contractor on the project, Tutor Perini, based in Sylmar, California, told us in a statement that safety is “of the utmost importance” on all of its jobsites. It acknowledged the fire suppression system was indeed “temporarily disconnected” that night, but said it wasn’t to save money from a discharge. Tutor Perini contends it was due to complete change order work Muni had sought.
Tutor Perini blamed the fire on Muni, for having “rushed the process” of train testing, without proper monitoring, without giving the contractor time to finish system checks beforehand.
The exhaust fan system issue, the contractor said, is not relevant because even if it had worked, it was designed to clear the subway and not the power room. Still, a Muni report on the fire concludes that the fan’s failure “could have seriously impaired efforts” to clear the subway, had smoke gotten in.
Muni officials did not respond to questions about the non-operation of the fire suppression and ventilation systems. But their final report – submitted to state CPUC regulators probing the fire -- promises numerous system upgrades. It doesn’t refer to any cost versus safety concerns, however, or discuss whether the fire could push off the scheduled opening date.
But the federal project monitor’s report from July concludes the currently planned opening date in November “could potentially be further delayed to the first quarter of 2023 due to the lack of availability of specialty spare parts” needed to repair the burned out electrical system.