The San Francisco Fire Department (SFFD) responded to an underground vault fire Tuesday afternoon after smoke was seen for blocks in downtown SF.
PG&E is synonymous with antiquated utility equipment — a company-wide fault that’s led to the vast majority of Northern California’s deadliest wildfires to date. In San Francisco, the embattled and bemoaned and monopolized utility operates hundreds of vaults, a.k.a. transformations, to supply the city’s 880,000-plus residents with (somewhat) stable electrical power.
3rd and Mission streets are closed as SFFD and @PGE4Me address an underground vault fire.
The intersection will remain closed, unknown ETA to reopen. Seek alternate routes. https://t.co/pasIZX2Mt7 pic.twitter.com/LMAQHEtDJs— SAN FRANCISCO FIRE DEPARTMENT MEDIA (@SFFDPIO) February 6, 2024
Per San Francisco Public Works, all PG&E vaults must exist under certain guidelines; for example, all transformers in San Francisco need to sit at least six feet from a “path of travel,” like a sidewalk or bike lane. Some of these vaults are also installed underground, creating, ostensibly speaking, safer operating conditions… should something go awry.
On Tuesday, February 6th, something did go amiss when one of PG&E’s underground vaults in downtown San Francisco, located near Mission and 3rd streets, erupted in flames and started spewing black smoke visible for blocks.
Media staging 3rd / Minna https://t.co/LKCKtEcpLy
— SAN FRANCISCO FIRE DEPARTMENT MEDIA (@SFFDPIO) February 6, 2024
The “wires and stuff” caused one parking enforcement officer to be taken to a nearby hospital after they were exposed to the smoke; they’re reportedly in stable condition.
“Think of a bank vault but underground for wires and stuff,” SFFD Captain Justin Schorr, a spokesperson for the fire department, told SFGate at 1:30 p.m. “There may be flames underground, right now we have smoke coming from two of the vault access ports — also called manhole covers.”
At that time, smoke was still visible at the intersection, though the remnants of the recent atmospheric river were helping blow the smoke elsewhere.
Vault fires are difficult to put out — mainly because water can’t be used to control them, due to the live electrical components. Instead, SFFD is resorting to filling the subterranean area with carbon dioxide, efficiently suffocating the fire.
“A carbon dioxide unit will be used to displace the oxygen in the vault because we can’t put water on the live electrical unit,” Schorr explained to on-site media. “A fire engine squirts water, this specialized truck squirts carbon dioxide. They’ll introduce that carbon dioxide into the electrical vault and it will replace the oxygen. Without oxygen, the fire can’t burn. We’re waiting for that unit to arrive.”
It’s unclear if SFFD has yet to reopen the interesting; no update on their social media reflects the Mission and 3rd streets zone has been given since 1:51 p.m. Tuesday. But we’d recommend avoiding the area like your MAGA-loving aunt at the family function.
Feature image: Courtesy of San Francisco Fire Department Media
