A fiery explosion at a chrome polishing business in La Habra injured 11 workers, leaving two critically burned, authorities said.
The fire at Gorilla's Polishing Corp. was reported about 9:50 a.m., said Keith Mora, inspector with the Los Angeles County Fire Department, which covers La Habra under a contract. The fire was knocked down at 10:26 a.m. with about 50 firefighters at the scene.
Firefighters arriving at the business found the building engulfed in flames and smoke, with workers fleeing the blaze, Mora said.
Fire investigators believe an accumulation of dust and lint in a duct system may have caused the explosion and fire, said Inspector Scott Miller.
A group of Gorilla's Polishing workers sat away from the building after the blast, wiping at their smudged faces.
Employees at Stop Look Sign Co. were in a meeting less than a half-mile away when the explosion thundered, rattling their business and halting their conference.
Initially they thought it was an earthquake, the area having experienced one a few weeks ago, said owner Mike Dougherty.
"It just sounded like a big explosion," Dougherty said. "Our second thought was that was a sonic boom, kind of like a concussion."
In 2011, the California Division of Occupational Safety and Health found seven violations at the business, including failing to monitor for airborne contaminants, to establish an injury and illness prevention program and to provide information to employees about hazardous substances.
Gorilla's Polishing Corp. had the case closed in January 2013 after paying $1,975 in a formal settlement.
Times staff photographer Don Bartletti contributed to this report.