CAL Fire officials determined that electric power lines and failure of power poles caused part of the massive North Bay wildfires in California that eventually killed dozens of people and ravaged thousands of homes in October.

Officials completed a total of 12 investigations of more than 170 fires that burned at least 245,000 acres in Northern California. Nearly half of the fires were caused by a tree coming in contact with PG&E powerlines, CAL Fire said.

The fire agency said it believes eight of the fires could have possibly been prevented based on complying with utility law, including Adobe, Pocket and Atlas Fires.

"The loss of life, homes and businesses in these extraordinary wildfires is simply heartbreaking, and we remain focused on helping communities recover and rebuild. We look forward to the opportunity to carefully review the CAL FIRE reports to understand the agency’s perspectives. Based on the information we have so far, we continue to believe our overall programs met our state’s high standards," PG&E responded in a statement.

Hundreds of homeowners and relatives of those killed have sued PG&E.

"PG&E has been trying to duck responsibility for the fires, blaming everything from climate change to local fire departments and the state's liability laws," Patrick McCallum, co-chair of a coalition of people affected by the wildfires, said in a statement.

He said Cal Fire's report "puts the blame where it belongs — squarely on PG&E, confirming it was responsible for many of the fires that devastated so many lives."

"As victims, we see the report as an important step toward rebuilding and recovery," McCallum said.

Sen. Bill Dodd, a Democrat who represents the Napa area, called the report's findings "disappointing and deeply concerning."

He has introduced legislation that would require electric utilities to update wildfire plans to determine when they need to cut power to lines during harsh weather and boost infrastructure.

"I'm calling on PG&E, utilities across the state and the Public Utilities Commission to step up and ensure they are meeting their legal obligations to maintain power lines in a safe manner," Dodd said in a statement. "It's inexcusable and it can't be allowed to happen again."



More than 8,000 structures across Northern California's wine country were wiped out by the fires, hundreds of thousands of acres were scorched and 44 people were killed as a result of the blazes.

Redwood Fire (Mendonico County):

Caused by tree of parts of trees falling onto PG&E powerlines, according to CAL Fire.

The Sulphur Fir

Sulphur Fire (Lake County):

Caused by the failure of a PG&E owned power pole, resulting in the power lines and equipment coming in contact with the ground, CAL Fire said.

Cherokee Fire (Butte County):

Caused by tree of parts of trees falling onto PG&E powerlines, according to CAL Fire.

37 Fire (Sonoma County):

CAL Fire investigators said they determined the cause of the fire was electrical and was associated with the PG&E distribution lines in the area.

Blue Fire (Humboldt County):

A PG&E power line conductor separated from a connector, causing the conductor to fall to the ground, starting the fire, CAL Fire said.



Norrbom Fire, Adobe Fire, Partrick Fire, Nuns Fire:

These series of fires that merged in Sonoma and Napa counties were caused by a tree falling onto a power line, CAL Fire said.

Pocket Fire (Sonoma County):

CAL Fire determined the fire was caused by the top of an oak tree breaking and coming into contact with PG&E power lines.

Atlas Fire (Napa County):

At one location, it was determined a large limb broke from a tree and came into contact with a PG&E power line. At the second location, investigators determined a tree fell into the same line, CAL Fire said.

CalFire investigators are still probing other fires in October and December, including the deadliest blaze in Napa and Sonoma Counties, which PG&E has argued was started by wires belonging to a private homeowner.

The Associated Press contributed to this report.

Refresh this page for more information on this breaking news story.