California’s largest wildfire was caused by a hammer, Cal Fire says

The largest wildfire in California history was an accident started by a claw hammer.

Cal Fire said Thursday that the Ranch Fire last July began when a property owner in Potter Valley, in Mendocino County, was installing a shade barrier. After disturbing an underground nest of yellow jackets, the man hammered a two-foot-long concrete stake into the ground to plug the hole, according to Cal Fire’s investigative report.

The hammering created a spark that lit up a patch of tall grass. Winds were strong, conditions were dry and the fire grew out of control. The property owner was unable to douse the flames.

The fire, which started July 27, eventually burned a total of 410,203 acres across Mendocino, Colusa, Glenn and Lake counties, making it the largest fire in state history in terms of acreage. The Ranch Fire burned 280 homes and other buildings and left a firefighter from Utah dead.

The property owner wasn’t identified, and Cal Fire said no charges will be filed.

“This was a complete accident,” said Cal Fire deputy director Michael Mohler.

He said it’s unusual, but not unprecedented, for a major fire to be ignited by a spark from a hammer. “It has happened before .... It just shows how receptive these fuel beds are (to fire).”

The Ranch Fire was one of two fires that made up what Cal Fire called the Mendocino Complex, which burned a combined 459,123 acres.

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