(CN) – California’s fire agency said 12 separate wildfires responsible for the death of at least 15 people were caused by downed power lines maintained by Pacific Gas & Electric.
The California Department of Forestry and Fire Protection released the results of its investigation Friday afternoon, determining the deadliest and most economically destructive firestorm in California history was created by downed power lines, distribution lines and the failure of conductors and power poles.
The fires all began late at night on Oct. 8, 2017, or in the early morning hours of Oct. 9, when high unrelenting winds not only caused tree limbs to break off, creating many of the fires, but facilitated the rapid spread of the forest fire.
The following is a summary of each of the 12 fires and their respective causes:
The Atlas Fire, which began outside Calistoga in Napa County, eventually burned about 51,000 acres and was responsible for the deaths of six people and the destruction of 783 structures. The fire started in two separate places when a limb broke from a tree and made contact with a power line, according to the investigation.
The Redwood Fire, another large and intensely destructive fire that burned about 36,000 acres in Mendocino County, killed nine people and caused damage to or completely destroyed 43 structures was also caused by tree limbs falling into power lines.
The Nuns Fire, which began as at least five separate fires before merging and creating a complex fire, burned about 56,000 acres, while killing three and destroying about 1,350 structures. Four of the five spot fires were created when tree branches broke off and hit power lines, while the final fire was created when power lines toppled, hit the ground and created a ground fire that spread to the canopy.
The Pocket Fire ravaged about 17,000 acres and destroyed six structures. Cal Fire determined the fire started when the top of an oak tree broke off and hit power lines in proximity.
The Sulphur Fire, which burned an approximately 2,000-acre swath of forest in Lake County, was caused by the failure of a power pole, which hit the ground and created a spark that turned into the fire.
The 37 Fire, responsible for the destruction of three structures and the burning of about 1,660 acres, was electrical in nature and is believed to be caused by PG&E distribution lines.
The Cherokee Fire burned about 8,000 acres in Butte County, destroying six structures. Tree limbs coming into contact with power lines sparked the blaze.
The Blue Fire started in Humboldt County and burned a total of 20 acres. The cause was a line coming loose from a PG&E maintained conductor.
PG&E issued a statement on Friday saying they welcomed the Cal Fire report.
“The loss of life, homes and businesses in these extraordinary wildfires is simply heartbreaking, and we remain focused on helping communities recover and rebuild,” the electric utility provider said in a statement. “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.”
Despite the pending nature of the investigations, PG&E has been named in several lawsuits throughout the state claiming the North Bay Fires were caused due to PG&E’s negligence and improper maintenance.
In a statement, state Sen. Bill Dodd, D-Napa, said it was “disappointing and deeply disturbing” to learn of the investigation’s results.
“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. “It’s inexcusable and it can’t be allowed to happen again. That’s why I’ve introduced legislation to develop new standards and oversight for utilities.”
Senate bills 901 and 1088, both proposed by Dodd, would require electric utilities to update their wildfire protection plans and create a utility infrastructure.
Cal Fire is still investigating the source of other destructive fires that occurred last October and December.