A faulty catalytic converter on a pickup truck was blamed Tuesday for sparking a series of brush fires that broke out along the 60 Freeway in Diamond Bar, threatening expensive hillside homes and forcing students to seek shelter in a gymnasium when their campus was clouded in smoke.
At least eight fires were reported about 11:45 a.m. as the vehicle spewed out sparks and flames in the grass and brush-covered terrain next to the freeway, authorities said.
Witnesses told The Times that the blazes were spread fairly evenly along the freeway, a busy east-west artery that links Los Angeles to the San Gabriel Valley and San Bernardino County.
"It looked like every 500 yards someone had taken a Molotov cocktail and thrown it off the freeway," said Retha Quince, who was driving home when she saw the smoke rising from the fires.
Authorities said they were still investigating the cause of the blazes, but added that the catalytic converter appeared to have been shooting out "hot material," said Capt. Mark Savage of the Los Angeles County Fire Department.
The driver of the 2004 Ford pickup, who was followed by an off-duty police officer, was detained for questioning when he drove through Ontario. He was released Tuesday afternoon, authorities said.
"It's more than likely that this was an accident, and no arrests will be made," said Nicole Nishida, a spokeswoman with the Los Angeles County Sheriff's Department.
As flames burned up the dry fuel, students at nearby Diamond Ranch High School took shelter in the gymnasium and prepared to be evacuated, officials said.
Worried parents, meanwhile, rushed to the school. But they were stopped at a roadblock set up by authorities in front of the only entrance to the campus.
Dozens of nervous parents waited on a smoky freeway overpass on Phillips Ranch Road, talking on cellphones or huddling with one other.
For mother Laura Perez, 38, being unable to see her 15-year-old son, Cristian, was frustrating. He had called her from his cellphone earlier.
"He sounded afraid," she said. "I wish I could be there for him."
Some students, like freshman Jaclyn Martinez, were picked up by parents who found a way around the roadblock.
Jaclyn, 15, said she had been eating lunch outside when people began running to see the thick clouds of smoke.
"Some kids were panicking," she said. "I held my sweat shirt over my mouth the whole time."