A claw hammer sparked the 2018 Ranch Fire, the largest wildfire in modern California history, according to a report issued by Cal Fire on Thursday.

The Ranch Fire, which broke out July 27, 2018, joined with other fires to scorch about 459,000 acres as the Mendocino Complex Fire, began as a spark thrown when a property owner in Porter Valley outside of Mendocino struck a metal stake with a hammer.

The property owner was attempting to install a shade barrier when the spark combined with exceedingly dry conditions and heavy winds to become a wildfire.

Cal Fire’s deputy director Michael Moeller told the Fresno Bee the incident was a “complete accident.” The property owner will not be charged.

The Ranch Fire alone burned about 410,000 acres, qualifying it the largest fire in state history. A firefighter from Utah was killed while fighting the blaze and four others were injured.

The blaze also destroyed 280 buildings and caused about $250 million in damage.

The fire started in the early morning hours near the community of Pulga in Butte County, the report reads. The tinder-dry vegetation and Red Flag conditions consisting of strong winds, low humidity and warm temperatures promoted this fire and caused extreme rates of spread, rapidly burning into Pulga to the east and west into Concow, Paradise, Magalia and the outskirts of east Chico.

The investigation identified a second ignition sight near the intersection of Concow Rd. and Rim Rd. The cause of the second fire was determined to be vegetation into electrical distribution lines owned and operated by PG&E. This fire was consumed by the original fire which started earlier near Pulga.

During the calendar year 2018 there were more than 7,571 wildfires that burned more than 1.8 million acres within the state of California.

— By Matthew Renda