It was not immediately clear what caused the blast at the Los Angeles County Sheriff’s Department’s Biscailuz Training Academy center. No one else was injured, officials said.

At least three people have died in an explosion at a Los Angeles County Sheriff’s Department’s training facility on Friday morning, according to US Attorney General Pam Bondi.

The explosion was reported about 7:30 a.m. at the Biscailuz Training Facility, Los Angeles County Sheriff’s Department spokesperson Nicole Nishida said. It was not immediately known what caused the explosion or what the deputies were doing at the time.