A hot piece of metal flung from the brakes of a car descending the Cuesta Grade was the cause of a 10-acre brush fire and ensuing traffic delays Sunday entering San Luis Obispo, Cal Fire investigator Zach Nichols told The Tribune on Monday.
The blaze on the Grade was one of at least six small fires that have scorched San Luis Obispo County since Sunday. All were contained, and no injuries were reported, Cal Fire information officer Tina Rose told The Tribune.
“High temperatures, low (humidity), wind and bone-dry vegetation coupled with human carelessness are to blame,” Rose said in a news release Monday night.
“We’re full on into the peak of fire season,” Rose said, which usually doesn’t arrive until September. “This type of fire behavior doesn’t happen until the end of summer.”
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Cal Fire has added at least one 17-man crew this week in anticipation of the danger, she said, adding that the agency normally has about six crews in the field.
The cause of the fire at the base of the Cuesta Grade was determined when Nichols found a piece of metal in a burnt piece of grass on the southbound gutter of the highway, and from there could deduce where the fire had spread.
Because of a lack of rain, the heated metal can cause dry grasses to ignite into flame.
Nichols said that as drivers descend south on the steep Grade, they often brake hard at the base to reduce speed, which heats up the brakes and causes pieces to fly off.
“It’s extremely common for a brake component or exhaust component to start a fire,” he said.
Cal Fire and the Morro Bay Fire Department extinguished a house fire Sunday evening on the 2900 block of Elm Avenue in Morro Bay that destroyed a garage and caused $50,000 in damage. The fire was fully extinguished after 22 minutes — just before it spread to a nearby residence and a trailer that was parked in the driveway.
The cause of the Morro Bay fire was still under investigation Monday, but arson was not suspected.
On Monday, Cal Fire battled blazes throughout the county.
At 3:30 p.m., a vegetation fire broke out at the California State Park Pismo Beach Campground on Pier Avenue near the entrance of the Oceano Dunes Vehicular Recreation Area, threatening numerous structures and forcing campers to temporarily evacuate. At the height of the fire, 83 firefighters were battling the blaze on the ground, assisted by two air tankers and two helicopters. The fire burned approximately four acres.
Rose said state park rangers detained two people on suspicion of starting the fire, although no one was taken into custody. Officials are still investigating but think the blaze was probably caused by humans, she added.
Also on Monday, Cal Fire contained two brush fires of two acres each in North County — one west of Paso Robles on Jack Creek Road off Highway 46, and one east of Santa Margarita along Parkhill Road — Rose said.
One person received a misdemeanor citation in the fire west of Paso Robles for starting the fire by mowing dead grass with a lawnmower.
“That’s carelessness,” Rose said. “Fuel-driven pieces of equipment throw sparks. Some are only designed to mow green grass.”
That person — who was not identified — will be charged with all the costs of putting out that fire.
The other brush fire was caused by electrical equipment, Rose said, though no further details were available.
Of the five fires reported Monday, “The majority of them were caused by humans,” Rose said.
The only exception was a spot fire at the intersection of Orcutt Road and Lopez Drive near Arroyo Grande, which was started Monday afternoon when a bird flew into power lines, caught on fire and fell to the ground.
“We can’t blame the bird,” Rose said, adding that a local resident got the small blaze under control “right away.”