By Steve Gorman
LOS ANGELES (Reuters) - The devastating Thomas Fire that killed two people and destroyed more than 1,000 structures northwest of Los Angeles in December 2017 was sparked by power lines owned by Southern California Edison Co, fire officials said on Wednesday.
An investigation of the fire's origins found that high winds blew Edison power lines into one another, creating an electrical arc that "deposited hot, burning or molten material" into dry vegetation on the ground, setting off the blaze, the Ventura County Fire Department said in a statement.
In a 70-plus page report, investigators also cited several possible criminal violations by Edison in connection with the fire, including involuntary manslaughter, reckless arson and a health-safety code breach for carelessly or negligently causing a fire.
A review by the state attorney general will decide whether criminal charges will be brought.
The company has acknowledged that witnesses reported seeing a roadside fire in the vicinity of an Edison power pole near one of the fire's points of origin at about the time it started, and that its equipment was associated with ignition of the blaze.
But in a statement on Wednesday, Edison said a second ignition point not linked with the utility's power lines may have been independently responsible for a significant portion of damage caused by the overall fire.
"A final determination on cause and responsibility will only be made through the legal process," Edison said.
The investigation was jointly conducted by county and state fire officials and the U.S. Forest Service.
The report came a day after prosecutors in four Northern California counties said they had found insufficient evidence to criminally charge another major utility, PG&E Corp, in a separate firestorm ignited by its power lines in October 2017.
PG&E, seeking bankruptcy protection in the face of billions of dollars in potential civil liability from those fires, was cited for safety code violations stemming from eight blazes for which it was investigated. Like the Thomas Fire, the so-called North Bay fires two months earlier was driven by extremely high winds.
The Thomas blaze burned for nearly 40 days as it threatened the towns of Santa Paula, Ventura, Ojai and Fillmore, scorching nearly 282,000 acres in the Ventura and Santa Barbara county foothills along the Southern California coastline.
At the height of the conflagration, more than 100,000 people were forced to flee their homes, and as many as 9,000 fire and emergency personnel battled the blaze, with crews from across the Western United States sent to help.
One firefighter and one civilian died in the blaze, which ranked for a time as the largest wildfire in state history in terms of acreage burned.
Mudslides unleashed by torrential rains drenching the fire-ravaged area in January swallowed dozens of homes and killed at least 20 people.
The utility and its parent company, Edison International, recorded a $4.7 billion charge before recoveries and taxes in the fourth-quarter, owing to wildfires.
(Reporting by Steve Gorman in Los Angeles; editing by James Dalgleish and Lisa Shumaker)