The Apple fire in Riverside County, California, which has burned more than 26,400 acres and is only 5 percent contained, was ignited by a malfunctioning diesel vehicle, fire officials announced on Monday.
The California Department of Forestry and Fire Protection said in a statement that on Friday evening, the vehicle released burning carbon from its exhaust system, which sparked the fire in Cherry Valley, an unincorporated town about 75 miles east of Los Angeles. Anyone with any information on the vehicle is asked to contact authorities.
The blaze has spread across hillsides and up the side of Mount San Gorgonio, destroying one home and two outbuildings. Nearly 8,000 people have been evacuated, and so far, no injuries have been reported. There are more than 2,300 firefighters on the scene.
"Much of the fire activity is being driven by the record-low moisture content of the vegetation in the area combined with high temperatures and low relative humidity," fire officials said on Monday afternoon. "These conditions are contributing to active fire behavior both day and night."