Three deputies were killed Friday in an explosion at the L.A. County Sheriff’s Department’s Biscailuz Center Training Academy in East L.A., the deadliest incident for the agency in more than 160 years.

A veteran investigator, a respected mentor and a skilled technician — the t hree arson investigators killed in an explosion at the Biscailuz Center in East LA were remembered as the “best of our department” by Los Angeles County Sheriff’s Department leaders.