Marin County fire officials blame a downed PG&E power line for Monday’s 150-acre Irving fire that threatened 150 homes near Lagunitas.
The fire, which was 100 percent contained Friday, burned on Barnabe Mountain in Samuel P. Taylor State Park.
Marin County Fire Battalion Chief Graham Groneman would not specify what may have caused that line to go down during light winds.
“That is purely speculative at this time,” Groneman said about what brought down the line. “We have a team of investigators out there looking at it.”
PG&E maps show a power outage at Arroyo Road and Portola Avenue in the town of Lagunitas after the fire started at 7 p.m. The outage left the Dickson county fire lookout and several communication towers on Barnabe Peak without power.
In a statement Wednesday, PG&E officials said they are assisting Marin County Fire in the investigation. Spokesman Matt Nauman said 150 customers lost power in the fire but service was restored to most of them by Tuesday.
The utility called the cause of the fire "preliminary."
“We are in the middle of fire season, and as part of PG&E’s Community Wildfire Safety Program, we are monitoring fire conditions from our Wildfire Safety Operations Center in San Francisco 24/7, to determine what, if any additional threats the fire may pose to our lines and facilities,” Nauman said in the statement.
Cal Fire has blamed PG&E power lines for many of the North Bay fires last October, citing vegetation clearance violations in several of them. PG&E’s use of reclosers – automated circuit breaker technology that has been blamed for wildfires as far as Australia – has been tied to at least one of the fires.
Reclosers automatically send three bursts of power down a line when a power interruption has been detected. If the problem is only temporary, service can resume. But in the case of downed lines, that current can spark fires.
PG&E says it is now curtailing using that technology during fire season. It’s unclear if a recloser was used during Monday’s fire in Marin.