"After a very meticulous and thorough investigation, CAL FIRE has determined that the Camp Fire was caused by electrical transmission lines owned and operated by Pacific Gas and Electricity (PG&E) located in the Pulga area", the agency said. Strong wind gusts blew hot embers a mile or more, creating multiple fires.
Cal Fire said transmission lines owned and operated by the San Francisco-based utility started the November 8 fire in the Pulga area that almost destroyed the town of Paradise in the Sierra Nevada foothills.
CEO Bill Johnson was testifying before the California Assembly's Utilities and Energy Committee when state fire authorities made their announcement.
The full Camp Fire investigative report has been forwarded to Butte County District Attorney Mike Ramsey, Cal Fire concluded.
The utility, which filed for bankruptcy protection in January, had said in February it was "probable" that one of its transmission lines sparked the blaze.
Named after Camp Creek Road near the first ignition point, the Camp Fire caused at least 85 civilian fatalities and several injuries to firefighters and residents.
PG&E had reportedly considered cutting power in the area because of the high winds and risky conditions but chose not to do so.
California Gov. Gavin Newsom said in a Wednesday filing that PG&E shouldn't get an extra six months to reorganize.
State fire investigators have determined that transmission lines owned by Pacific Gas & Electric Co caused the deadliest and most destructive wildfire on record in California, a blaze that killed 85 people a year ago, officials said on Wednesday. He said the utility's request continues to show it lacks an urgent focus on improving safety.
The company faces dozens of lawsuits from Camp Fire victims and billions of dollars in potential liabilities.