Arcing PG&E lines blamed for 2 small blazes

For the first time since flames tore across the North Bay in October, government fire investigators have pinned the blame for some of the fires on Pacific Gas and Electric Co. power lines swaying and arcing in a fierce wind.

Incident reports from the Santa Rosa Fire Department found two small fires that started within the city on the night of Oct. 8 and early morning of Oct. 9 were likely sparked by electrical lines arcing and setting vegetation on fire during a windstorm.

In one of the two incidents, along Brush Creek Road, electrical lines kept arcing and starting more flames even after firefighters arrived. The other fire covered by the reports destroyed two homes along Sullivan Way before firefighters extinguished it.

“Ignition of vegetation resulted from the arcing overhead power lines that were damaged by the extreme winds,” reads the Sullivan Way incident report.

Neither blaze was connected to the massive Tubbs Fire, which started near Calistoga and swept into Santa Rosa in the early morning hours of Oct. 9, destroying entire neighborhoods.

Investigators with the California Department of Forestry and Fire Protection, or Cal Fire, are trying to determine the causes of the Tubbs Fire and the other major blazes that erupted across Northern California that evening, leveling 8,889 buildings and killing 45 people. Cal Fire may not release the results of its investigations for months.

But many homeowners have already sued PG&E, blaming the utility’s power lines for starting the fires. Sonoma County supervisors voted unanimously last week to do the same. And PG&E’s own records show that the company found damaged equipment at the suspected ignition points for all four of the most destructive fires across the North Bay that night, including the Tubbs Fire.

The reports from the Santa Rosa Fire Department will probably become fodder for those lawsuits, even though the small fires covered in the report were not directly related to the larger blazes driving the litigation. PG&E, in response, emphasized that the major fires remain under investigation.

“There has been no determination by Cal Fire on the causes of any of the fires, and we remain focused on doing everything we can to help Sonoma and Napa Counties recover and rebuild,” said spokeswoman Ari Vanrenen in an email. “Our thoughts continue to be with everyone impacted by these devastating wildfires.”

Cal Fire Deputy Chief Scott McLean said he was not aware of any other North Bay jurisdictions conducting their own investigations of fires that broke out Oct. 8 and 9, during the event that state officials are now calling a “fire siege.” In contrast, several city, county and state agencies are investigating December’s Southern California wildfires.

“As far as the North Bay fires, the siege, we have the lion’s share,” McLean said.

Small fires burst out across Sonoma and Napa counties that night, some of them merging into larger blazes, while others were extinguished by fire crews. Both of the incident reports from the Santa Rosa Fire Department concern blazes that were quickly contained.

The first started around 10:13 p.m. on Oct. 8, near the Brush Creek Montessori School at 1569 Brush Creek Road. Crews arrived to find grass and a chicken coop on fire, and electrical lines arcing as they swayed in the wind. One of the crews reported seeing trees hitting the lines. The fire also burned a wooden handball board at the school before it was extinguished.

The second blaze started around 12:17 a.m., Oct. 9, near 4822 Sullivan Way. According to the report, a neighbor spotted arcs from an electrical line, and a PG&E field technician told a fire department official that a line had broken in the trees along the road. Flames burned up a slope and into two homes. The only injury reported, however, was a firefighter spraining his knee.

David R. Baker is a San Francisco Chronicle staff writer. Email: dbaker@sfchronicle.com Twitter: @DavidBakerSF