LA County firefighter killed, another injured by explosion while battling truck fire at quarry near Palmdale

At least one Los Angeles County firefighter was killed Friday while battling a fire at a quarry near Palmdale when there was some sort of explosion, according to the department.

It happened shortly after 2 p.m., at which time crews were dispatched to the 6500 block of E. Avenue, a rock quarry near Pearblossom Highway, for a truck fire in the area, fire officials said of Los Angeles County.

It is still unclear what triggered the explosion and an investigation is underway.

A second firefighter was rushed to a nearby hospital for injuries sustained in the explosion, according to LACoFD Chief Anthony C. Marrone. They are expected to be released later Friday.

The identity of the victim has not yet been released.

Chief Marrone said they have not yet released his identity because he does not know if everyone close to the firefighter has been notified. He said he was a 19-year veteran of the department and was a father and husband.

The Los Angeles County Sheriff's Department's Homicide Unit, which specializes in arson and explosives, is investigating the case.

It is still unclear what exactly caused the fire and what exploded.

With SkyCal above, a massive Caterpillar front loader could be seen with large flames of black smoke still billowing from its engine area.

An American flag was displayed on the victim's body tens of meters from the vehicle, which firefighters were still spraying with water from a distance for hours after the death.

This is a developing story. Check back for more details.