A vehicle traveling on Highway 50 sparked the fire that shut down the freeway during the evening commute Monday and resulted in a power outage affecting thousands of El Dorado County residents.
"The cause of the fire was related to a vehicle driving on eastbound Highway 50," Battalion Chief Chris Anthony of the California Department of Forestry and Fire Protection said in a written statement.
Fire crews were dispatched at 4:03 p.m. to a report of a wildland fire at eastbound Highway 50 and Ponderosa Road. Fire officials said the fire was found to be between the freeway and Durock Road near a PG&E power substation. Because of the location, the California Highway Patrol closed Highway 50 and Durock Road in both directions until firefighters were able to get a handle on the blaze, according to a Cal Fire news release. The fire was reported fully contained at 8:31 p.m.
PG&E cut power to approximately 49,000 customers so emergency crews could safely fight the fire. Cal Fire officials said initial reports of a downed power line was not true, but power lines were arcing and some transformers exploded during the initial stages of the fire.
"Firefighter safety is our primary concern," Cal Fire Unit Chief Kelly Keenan said in a written statement. "As firefighters arrived at the scene, they initially could only suppress the perimeter of the fire due to hazards the substation and overhead power lines posed."
Anthony said the fire began near the side of the highway and quickly spread toward houses, businesses and the substation.
"This is why it is so critical for everyone to make sure their vehicles are properly maintained because, as we witnessed (Monday), an improperly maintained vehicle can have far-reaching consequences," he said.
When a vehicle is not well maintained, fire officials said, the exhaust system can become overtaxed, allowing fuel to enter the exhaust system, which in turn overheats the catalytic converter, which melts and disintegrates as the car is driven. Pieces of the catalytic converter exit the muffler at about 1,200 degrees and can bounce into dried grass along the edge of roads and start fires.
Another common cause of wildland fires are tires that blow out because they are improperly inflated. The tires shred into pieces and bounce off the road into dried vegetation that during the summer months can catch fire.
Fire officials also warn that towing vehicles, boats, campers, jet skis and other equipment place added stress on a vehicle's transmission, which can spell disaster if the transmission has not been properly maintained.