What Causes California Fires? Power Lines Can Be a Contributor.

Investigators are still working to identify what caused the spate of fires that ignited around Los Angeles last week, but residents are concerned that electrical infrastructure may have sparked at least one of them.

Since 1992, more than 3,600 wildfires in California have been related to power generation, transmission and distribution, according to data from the U.S. Forest Service. Some of the most destructive fires have been traced back to problems with utility poles and power lines.

CalFire releases data on past large wildfires and determines their causes in different natural and human-related categories, such as lightning or arson. The agency lists more than 12,500 fires since the late 1800s, though the causes of more than half are unknown or unidentified.

Lightning and use of equipment are among the most common known causes, but over the past few decades, the share of fires known to be caused by power infrastructure has grown across the state.

Residents of Altadena, Calif., sued Southern California Edison on Monday, saying the utility’s electrical equipment set off the Eaton fire, which has burned more than 13,000 acres and 5,000 structures in the city and neighboring areas. The company has said it is investigating the fire’s origin.

Power distribution lines were found to have caused some of California’s largest-ever fires in recent years.

The Thomas fire in 2017 was started when high winds forced Southern California Edison’s power lines to collide, a situation known as “line slap.” Burning material fell to the ground in the Upper Anlauf Canyon, about 35 miles from the current Palisades fire, and the resulting fire burned for almost 40 days.

The 2018 Camp fire, in Northern California, started when an electrical arc between one of Pacific Gas & Electric’s power lines and a steel tower sent molten metal onto the underlying vegetation. That fire claimed more than 80 lives and destroyed over 18,000 structures.

In the summer of 2021, California’s largest single-source wildfire, the Dixie fire, started when a tree made contact with several of PG&E’s distribution lines near the Cresta Dam in Northern California. Electricity continued flowing in one of the lines, which started the fire, and nearly a million acres across four counties burned.

California isn’t the only state dealing with power-related wildfires in recent years. Texas’ largest wildfire, the Smokehouse Creek fire, burned over a million acres in 2024. Xcel Energy accepted responsibility for the fire after investigators found that high winds had broken a utility pole, causing a power line to fall and ignite the dried grasses below.

Similar situations have caused wildfires in Oregon as well. The 2020 Labor Day fires destroyed thousands of homes and killed at least nine people, in part, after power wasn’t shut down during high winds.