Three veteran Los Angeles County sheriff's deputies who specialize in arson and explosives investigations were killed when military-style ordnance detonated at a training facility on Friday morning, authorities said.
The department picked up two explosives overnight in the L.A. County community of Lakewood and had taken them back to the department's training facility in East L.A., law enforcement sources told NBC News.
One of those two military-style devices exploded, killing the three deputies.
The explosives specialists involved in Friday's accident had assisted police in Santa Monica on Thursday, and investigators were getting a warrant to go search that location — but it remained unclear if there was any connection, a department spokesperson said. Lakewood is 22 miles southeast of Santa Monica.
Friday was the deadliest day in more than a century and a half of department history, Sheriff Robert Luna said.
“This is, unfortunately, the largest loss of life for us as the L.A. County Sheriff’s Department since 1857," he said.
Los Angeles County firefighters were dispatched at 7:27 a.m. PT for an explosion by 1000 N. Eastern Ave. in East L.A., which is near the sheriff department's Eugene Biscailuz Regional Training Academy, 5 miles east of L.A. City Hall, officials said.
The dead were identified as Detective Joshua Kelley-Eklund, Detective Victor Lemus and Detective William Osborn, who were all on the Special Enforcement Bureau’s Arson Explosives Detail. Luna said they had 74 years of collective experience on the force.
"I’ve heard over and over the word 'elite' being used. I think sometime that that term gets overused. But if you’re familiar with our Special Enforcement Bureau, they’re the best of the best," Luna said. "They are fantastic experts, and unfortunately I lost three of them today."
Luna told reporters the investigation has just started so the cause is still not known.
"The thoughts of all Angelenos are with all of those impacted by this blast," L.A. Mayor Karen Bass said in a statement.
California Gov. Gavin Newsom said, "This is a heartbreaking day for California."
The FBI and the federal Bureau of Alcohol, Tobacco, Firearms and Explosives' National Response Team are assisting in the investigation.
LAPD Chief Jim McDonnell pledged his bomb squad, SWAT and K-9 teams to the sheriff's communities to free up resources for the investigation.
"We stand in solidarity with our Sheriff's Department colleagues during this incredibly difficult time and we remain ready to assist in any way we can," McDonnell said in statement.
Deputy Jason Zabala had the day off Friday and got a phone call about an accident.
“I think I was in shock at first, and then I remember when I was telling my wife, ‘I have to go to work’ — I just broke down,” he said. “These are individuals that I’ve known for better part of two decades.”
Zabala called the three people who lost their lives “some of the best deputies I’ve ever worked with.”
The L.A. County Sheriff's Department is the nation's largest local sheriff's agency.
Deputies patrol L.A. County courthouses, jails and unincorporated communities and provide police services to cities that contract with the department.
Friday's blast marks the deadliest law enforcement-related explosion in Southern California in nearly 40 years.
Zabala, the sheriff’s deputy who knew those who were killed, said that the job has risks and its share of heartbreak, including responding to the devastating wildfires that struck the Los Angeles area in January.
“You go through a lot as your career goes on in the sheriff’s department. But you’re never prepared for ‘Hey, three of your comrades just, just died today,’” he said. “It’s very hard to process, even with all that.”
