A deadly wind-driven wildfire that raged across the northern edge of Los Angeles last week started near the base of high-voltage transmission tower owned by electric utility Southern California Edison, company and fire officials said on Monday.

The company, a unit of Edison International, said through a spokeswoman that it had notified the California Public Utility Commission on Oct. 11, the day after the fire started, that “our system was impacted near the reported time of the fire.”

The “electric safety incident” report, a copy of which the utility provided to Reuters, identified the facility involved as a company-owned transmission tower near a traffic intersection in the foothills where the Saddleridge fire is thought to have erupted.

Los Angeles Fire Department spokesman Captain Erik Scott said Monday that the cause of the fire was uncertain. But he said investigators had traced the fire’s origin to a slope beneath the high-voltage tower near Saddle Ridge Road.

The Southern California Edison report does not state whether the tower is suspected of sparking the blaze, or whether the tower or the power lines were damaged by high winds that quickly spread the flames over thousands of acres. But the Edison spokeswoman, Susan Cox, confirmed that the tower in question belonged to the utility.

Edison had turned off power to some customers across the region as a precaution last week after extreme winds and dry weather raised the risk of wildfire. But a utility spokeswoman was quoted as telling the Los Angeles Times on Sunday that Edison “did not de-energize any power for the Saddleridge fire area.”

In Northern California, utility Pacific Gas and Electric Co (PG&E) faced increasing criticism from the governor and state regulators on Monday for its own wide-scale precautionary power shutdown, which preceded Edison’s by about a day but was seen as being poorly managed and communicated.

The Public Utility Commission on Monday ordered PG&E to undertake immediate “corrective actions,” and Newsom called for the company to provide credits or rebates to affected customers.

PG&E Corp CEO Bill Johnson defended his company’s actions, conceding “areas where we fell short” during the power cutoff but insisting PG&E made “the right decision.” He also noted that there were “no catastrophic wildfires” in the utility’s service area last week.

Origin Pinpointed, Cause Still Unknown

The Saddleridge fire was the latest in a string of severe California wildfires for which electrical utility equipment has been scrutinized as a possible flashpoint.

The blaze scorched nearly 8,000 acres, threatening more than 17,000 homes and triggered the evacuation of 100,000 people before a change in the weather helped firefighters subdue the conflagration over the weekend.

At last count, 75 homes or other structures were damaged or destroyed, and a man suffered a fatal heart attack while trying to defend his property from the flames.

Edison’s power lines were determined to have been the ignition source for a much larger fire in December 2017 that killed two people and destroyed more than 1,000 structures in Ventura and Santa Barbara counties, northwest of Los Angeles.

PG&E equipment was found to have sparked a flurry of wildfires that swept through wine country north of San Francisco Bay in 2017, as well as last year’s devastating Camp Fire, which killed 85 people in and around the Northern California town of Paradise.

PG&E, the state’s largest investor-owned utility, filed for bankruptcy in January, citing more than $30 billion in potential liabilities from the fires.