BUTTE COUNTY (CBS SF) — Cal Fire officials on Tuesday announced that the agency’s investigators have determined that the massive Dixie Fire was caused by Pacific Gas & Electric power lines.

Cal Fire issued the press release confirming the cause of the fire Tuesday afternoon.

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“After a meticulous and thorough investigation, Cal Fire has determined that the Dixie Fire was caused by a tree contacting electrical distribution lines owned and operated by Pacific Gas & Electric (PG&E) west of Cresta Dam,” the statement read.

The Dixie Fire broke out on July 13 in Butte County before it exploded in grown, spreading to Plumas, Lassen, Shasta and Tehama counties. The wildfire burned 963,309 acres, destroyed 1,329 structures and damaged 95 additional structures. It is the largest non-complex fire in California state history.

The utility had already been accused of causing the fire in lawsuits filed last September.

The lawsuits alleged the wildfire was sparked on July 13 following several blown fuses and PG&E equipment malfunctions off Highway 70 in the Feather River Canyon in Butte County. A power outage in the area was reported by PG&E’s outage system at 7 a.m. that day, but a PG&E troubleman did not arrive at the scene until after 4 p.m.

According to the complaint, plaintiffs say they believe the Dixie Fire was caused by a Douglas Fir tree leaning into PG&E’s high voltage distribution line, which the blown fuses were designed to protect. They allege that the fire happened because PG&E’s infrastructure was constructed to pass electricity through exposed power lines in vegetated areas, and because the company was negligent in maintaining and operating its equipment and in keeping appropriate clearance from surrounding vegetation.

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Although no formal findings had been reached at the time of the filing, PG&E acknowledged to regulators that a tree leaning into one of its power lines may have started the Dixie Fire.

PG&E is also facing a lawsuit filed by five Northern California counties over the massive fire that burned nearly 1 million acres last summer.

According to a statement obtained by Chico CBS affiliate KHSL-TV, Butte, Lassen, Plumas, Shasta and Tehama counties filed the suit in San Francisco Superior Court last October.

“Tehama County brings this action to recover public and natural resources lost, because PG&E failed to manage and maintain its high voltage infrastructure,” said Dennis Garton, chair of the Tehama County Board of Supervisors.

The lawsuit seeks damages for injuries to public resources, natural resources, lost revenues increased expenses, lost assets, infrastructure damages and other damages.

“PG&E must be held accountable for this devastating fire, and we expect PG&E to step up and do the right thing immediately to help our communities rebuild,” Garton went on to say.

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According to a filing with the SEC by the utility last November, PG&E is expecting a $1.15 billion financial hit from claims related to the monstrous Dixie Fire.