Four Los Angeles County Sheriff's Deputies were injured, two critically, in an explosion and fire this morning, at North County Correctional Facility (NCCF) at the Pitchess Detention Center. NCCF is located in Castaic, in the northern part of Los Angeles County. All four deputies were loaded into radio cars and rushed to Henry Mayo Medical Center, a few miles away. The current status of the deputies is unknown. 

The fire was allegedly burning in a trailer, possibly a mobile firing range, on the grounds of the facility. Firefighters continued their efforts to douse the flames more than an hour afterward, authorities reported.

According to the Los Angeles County Sheriff's Department, which described what happened as a "training incident," two deputies were transported for hospital treatment. The severity of their injuries was not immediately known.

The cause of the fire is still under investigation.

Due to the severity of the deputies' injuries, they were loaded into radio cars and transported to the hospital before LA County Fire Department resources could respond to the facility. All four deputies suffered severe burns to their bodies and other unknown injuries. Pitchess Detention Facility is a very large compound that has multiple facilities on the property, including four separate jail facilities, a SWAT training facility, an Emergency Vehicle Operators Course track, and a separate full-size firing range facility used for academy classes and professional training courses. Pitchess, also known as Wayside, is over 2,600 acres in size.

The mobile range facility is not inside the facility walls but outside the building itself. The range itself is a converted trailer commonly seen on semi-trucks. Like any typical indoor shooting range, these range trailers are equipped with industrial-strength ventilators and air filtration systems that remove lead particles and gunpowder residue from the air to keep the inside of the trailer safe for use. In addition to the air filtration systems, the ranges also store ammunition for several different calibers on the outside of the trailers in heavy-duty secured lockers. 

Range trailers are used by the entire department, with some trailers being permanently stationed at detention facilities like NCCF, as in this case. Others are transported around the county to different patrol stations and other facilities that are farther away from the department's two permanent weapons ranges, one being at Wayside and the other located at the Biscaluz Training Center in East Los Angeles. The trailers are used quite frequently by all sworn personnel, as well as all LA County Security Officers, to maintain their quarterly qualification requirements on all weapons carried on and off duty, as well as qualifying for "exceptional shooting status," like Expert Marksman or Distinguished Marksman. 

As a trained mobile range operator when I was on the job, these trailers were used quite extensively, and the maintenance required to keep them operational was frequent and extensive. The trailers are equipped with a desk station for the operator and two shooting stations that have electronically controlled target systems that can be set at ranges from one to 25 yards. It is a lot of equipment to maintain, and it is vital that this is done. I can't say what caused this incident today; however, it is very possible that there was a failure in the filtration system, or the filters were too saturated with lead and gunpowder residue, which could have caught fire and exploded.