Shelter in place lifted after downed power line causes outage in SF

Image 1 of / 1 Caption Close Shelter in place lifted after downed power line causes outage in SF 1 / 1 Back to Gallery

An incident that was initially described as two transformers exploding near Van Ness Ave. and Green Street was actually a damaged cross arm on a utility pole that caused a power line to fall onto the roadway, fire and utility officials said Friday night.

San Francisco firefighters responded to reports from callers of an explosion before 7 p.m. and found at least one power line strewn across the street, according to the San Francisco Fire Department.

Pacific Gas and Electric Co. crews determined that a cross arm — which supports the power lines on a utility pole — was either broken or damaged, causing the downed line and subsequent outage, said Carly Hernandez, a PG&E spokeswoman.

“It caused a loud ‘pop,’ which is where the confusion is,” said Lt. Jonathan Baxter, a public information officer with the fire department. “Crews did confirm that there was no explosion or fire. We do concur with PG&E’s assessment.”

Officials received reports of damage from the wire to vehicles, but no one was injured.

While there are transformers in the area of the downed wire, Hernandez said, no transformers exploded or were impacted by the downed line.

Officials could not immediately confirm how long the damaged cross arm had been in place, or expand generally on how often cross arms should be replaced.

One building was without power on Friday night, but fire officials did not say whether the building was residential or commercial. PG&E officials said three customers were impacted by the outage, Hernandez said.

Fire officials placed a temporary shelter in place order around Van Ness Ave. and Green Street for nearly two hours while crews deenergized the power line and cleared the scene.

The cause of the downed wire is still under investigation.

The order was lifted just before 8:45 p.m. on Friday.

Hernandez said PG&E crews expect to be on the scene for an unknown amount of time to make “necessary repairs” to restore power to impacted customers and to “ensure the scene is safe.”

San Francisco police officers also responded to the scene.

Lauren Hernandez is a San Francisco Chronicle staff writer. Email: lauren.hernandez@sfchronicle.com Twitter: @LaurenPorFavor