An explosion at a Los Angeles County Sheriff's Department training facility Friday left three deputies dead, officials said.The blast was reported just before 7:30 a.m. Pacific and occurred at the Biscailuz Center Training Academy in East L.

Three Los Angeles County sheriff’s deputies assigned to the arson explosives detail were killed in an explosion at a law enforcement training facility.

The investigation into the deaths of three L.A. County deputies, all killed by an explosion of military-style grenades thought to be inert continued Wednesday with police using a robot to search for possible explosives inside a storage unit.