How are wildfires started? A look at the causes of some of the worst in California history

WABC logo
Sunday, November 25, 2018
EMBED <>More Videos

These are the five most destructive wildfires in California history when measured by the number of structures destroyed.

As firefighters continue to work to contain the historically devastating Camp Fire, one question is on the minds of many who were affected: What started it?

RELATED: The deadliest wildfires in California history

The cause of the Camp Fire is still under investigation, but victims sued Pacific Gas & Electric last week, accusing the utility company of failing to maintain its infrastructure, thereby causing the fire.

PHOTOS: Camp Fire burns through Butte County, California

1 of 119
In this aerial photograph, an evacuee encampment is seen at a Walmart parking lot in Chico, California on November 19, 2018.
Josh Edelson for the Washington Post

The November 2018 fire, which is both the deadliest and most destructive in California history, is not the only recent wildfire whose cause is under investigation.

RELATED: Most destructive California wildfires in history

While the cause of some remains unknown, some, such as 2003's Cedar Fire, were determined to be started by human-related causes, while others, such as 2012's Rush Fire, were caused by Mother Nature.

Here's a look at some of the worst wildfires the state has seen, in chronological order, and what caused them.

CAMP (Butte County), Nov. 2018

The Camp Fire is both the deadliest and most destructive wildfire in California history.

Official cause: Still under investigation

CARR (Shasta and Trinity counties), July 2018

The Carr Fire destroyed 1,604 structures, making it nearly as destructive as the Witch Fire. At 229,651 acres, it was among the largest in state history. Eight people died as a result of the Carr Fire.

Official cause: Human Related

MENDOCINO COMPLEX (Colusa, Lake, Mendocino & Glenn counties), July 2018

The Mendocino Complex Fires were by far the largest in state history, burning more than 459,000 acres. The fires destroyed 280 structures and caused one death.

Official cause: Still under investigation

THOMAS (Ventura and Santa Barbara counties), Dec. 2017

At 281,893 acres, the Thomas Fire was the second largest fire in state history. It destroyed 1,063 structures and caused two deaths.

Official cause: Still under investigation

TUBBS (Napa and Sonoma counties), October 2017

The Tubbs Fire destroyed 5,636 structures. Until the Camp Fire, it was most destructive wildfire in state history. The Tubbs Fire was also among the most deadly recent fires, killing 22 people.

Official cause: Still under investigation

VALLEY (Lake, Napa and Sonoma counties), Sept. 2015

The Valley Fire burned 1,955 structures, one of the most destructive in state history.

Official cause: Electrical

RUSH (Lassen County), August 2012

The Rush Fire was among the state's largest at 271,911 acres in California (with an additional 43,666 acres in Nevada). Fortunately, it destroyed no structures and caused no deaths.

Official cause: Lightning

WITCH (San Diego County), Oct. 2007

The fire destroyed 1,650 structures, making it the sixth most destructive in state history. At 197,990 acres, it was also among the 10 largest.

Official cause: Powerlines

CEDAR FIRE (San Diego County), October 2003

The Cedar Fire killed 15 people and destroyed 2,820 structures. It is also the third largest in state history, burning 273,246 acres.

Official cause: Human Related

TUNNEL - Oakland Hills (Alameda County), October 1991

The Tunnel Fire was the third deadliest in state history, killing 25 people. It also destroyed 2,900 structures, making it the third most destructive.

Official cause: Rekindle

RATTLESNAKE (Glenn County), July 1953

The Rattlesnake Fire killed 15 people, one of the deadliest in state history.

Official cause: Arson

GRIFFITH PARK - (Los Angeles County), October 1933

This fire killed 29 people. Until the Camp Fire, Griffith Park was the deadliest wildfire in California history.

Official cause: Unknown

The Associated Press contributed to this report.