LOS ANGELES (AP) — Sparks from an idle transmission tower owned by Southern California Edison caused the 2025 Eaton fire in the Los Angeles area that killed 19 people and destroyed more than 9,400 homes and businesses, Los Angeles County fire officials said in a report released Tuesday.

It took firefighters nearly a month to extinguish the blaze, which scorched 22 square miles (57 square kilometers). The Eaton fire burned at the same time as the wind-whipped Palisades fire. An AP analysis at the time showed both blazes torched more urban area than any California fire in decades.

The Eaton fire was caused by electrical arcing on the utility’s out-of-service tower atop a ridge covered with dry fuel, the agency said in a statement. When bare, uninsulated wires touch or come close together it can cause arcing, which is when electricity jumps through the air, producing sparks.

The report said SoCal Edison was responsible for maintaining and operating its electrical lines and equipment “in a manner that would minimize the risk of catastrophic wildfire posed by them.”

Utility has acknowledged potential involvement

The utility indicated previously its equipment may be involved. In early reports to the California Public Utility Commission, SoCal Edison said it detected a “fault” on one of its transmission lines around the time that the Eaton fire started.

Kathleen Dunleavy, a spokesperson for SoCal Edison, said the utility is reviewing the report.

“We have taken our potential role in the start of this fire seriously from the very beginning,” Dunleavy said. She said SCE previously acknowledged “it was likely our equipment was associated with the ignition of the Eaton Fire.”

Utilities have been blamed for many of California’s most destructive fires in recent years.

SoCal Edison, which provides electric service to about 15 million people in California, has paid out hefty sums over the years due to its equipment sparking fires, including $2.2 billion to settle insurance claims from the deadly, destructive Woolsey wildfire in 2018.

Dunleavy said the utility has claims against other agencies over issues such as emergency response and the condition of surrounding vegetation.

“Ignition is different from spread,” Dunleavy said. “A fire of that magnitude – it’s never just one thing. There are numerous factors.”

The utility is facing hundreds of lawsuits from fire victims, insurers and government entities related to the Eaton fire. The U.S. Department of Justice has also sued the company over damage to National Forest land, and has asked for more than $40 million in damages to the federal, state and local governments.

Joy Chen, executive director of Every Fire Survivor’s Network, said the report confirms what thousands of fire victims already knew about what caused the blaze.

“The real question is who pays?” asked Chen, whose home sustained smoke damage.

Messages were sent to state and county prosecutors asking if SoCal Edison could face criminal charges.

Another California utility, Pacific Gas & Electric, filed for bankruptcy after its outdated equipment ignited wildfires in California that killed more than 100 people and wiped out entire towns, including Paradise. The utility pleaded guilty to 84 counts of involuntary manslaughter in connection with the 2018 Camp Fire.

The Los Angeles County Arson Fire Investigation Unit jointly conducted the investigation with California Department of Forestry and Fire Protection or Cal Fire. The blaze was sparked during extreme weather conditions that included high temperatures, low humidity and powerful winds. Two “electrical arcing events” occurred in quick succession, causing an unknown burning material to fall from the tower to the ground below, according to the report.

Investigators interviewed residents who saw flames

The report cites interviews with several residents who saw the fire in its early stages on Jan. 7, some who said it occurred below power lines. One witness who noticed flames under an electrical tower said “he observed an arc while watching the fire; he described it as a blue light,” the report said. The witness began taking photos around 6:25 p.m., then watched as the blaze spread rapidly amid heavy winds.

Another Pasadena resident told investigators she was doing dishes with her daughter when she observed a circle of orange sparks that turned into flames. “The circle of fire was located at the base of the transmission towers,” the report said.

Fire Chief Anthony C. Marrone said “while the cause has been determined, our focus remains on assisting our residents to rebuild their homes and livelihoods, and ensuring lessons learned drive meaningful and impactful change in memory of the 19 lives lost.”

The Palisades Fire was the most destructive blaze in Los Angeles to date and among the five worst in California’s history. That fire killed 12 people and destroyed more than 6,800 homes and buildings in Pacific Palisades. The fire ripped through hillside neighborhoods, destroying mansions with spectacular ocean views.

The man accused of sparking the Palisades Fire will be tried again this fall after his first federal arson case ended in a mistrial in June. Prosecutors said Jonathan Rinderknecht used a barbecue lighter on Jan. 1, 2025 to spark a blaze that burned undetected deep in root systems before flaring back up Jan. 7.

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Taxin reported from Santa Ana, California.

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