LITTLEROCK, Calif. (AP) — A Los Angeles County firefighter was killed and another was injured Friday after responding to a vehicle fire at a quarry in a desert community north of Los Angeles, authorities said.

An explosion occurred shortly after a firefighting crew arrived at the quarry in Littlerock around 2:10 p.m., killing the 19-year veteran firefighter who was based in the nearby city of Palmdale, L.A. County Fire Chief Anthony Marrone said.

Marrone hadn’t been to the site of the explosion and didn’t know how the fire in the front end loader started or what exploded. The Los Angeles County Sheriff’s office will conduct an investigation, he said.

Television images from the scene showed the front loader burning and sending thick black smoke into the air.

“I asked that everyone please allow our firefighters the space that they need to process our profound loss,” Marrone said.

A second firefighter who was near the blast was taken to Antelope Valley Medical Center but did not suffer any serious injuries and would be released later Friday, he said.

The name of the dead firefighter would be released once his wife and children were notified, Marrone said.

Los Angeles County Supervisor Kathryn Barger, whose district includes the Littlerock area, said her heart was heavy to learn of a firefighter losing his life on the line of duty.

“It’s a sobering reminder of the dangers our first responders face every day,” she said in a statement. “We owe them our steadfast support as they grapple with this loss.”