A veteran investigator, a respected mentor and a skilled technician — the three arson investigators killed in an explosion at the Biscailuz Center in East L.A. were remembered as the “best of our department” by Los Angeles County Sheriff’s Department leaders.

With decades of combined experience across a variety of units and stations, Detectives Joshua Kelley-Eklund, Victor Lemus and William Osborn had deep law enforcement experience before joining the Sheriff’s Department’s elite Special Enforcement Bureau’s Arson Explosives Detail.

“There are no words to express the pain and sorrow we feel,” L.A. County Sheriff Robert Luna said in a statement in which he identified the three men late Friday. “These heroes represented the best of our Department, exemplifying courage, integrity and selfless service.

“This is not only a heartbreaking loss for their families, but for all of us.”

Detective Kelley-Eklund joined the department in 2006. After working assignments at the Pitchess Detention Center North and the North County Correctional Facility, he moved to the Lennox and South L.A. stations.

Kelley-Eklund mentored younger deputies as a field training officer before becoming a detective in the Narcotics Bureau and being assigned to the L.A. Impact Team. As part of that assignment, he spent years investigating complex crimes that led to large narcotics seizures and the arrests of murder suspects, department officials said.

He is survived by his wife, Jessica, and their seven children, officials said.

Detective Lemus joined the department in 2003. He initially worked at the Twin Tower Correctional Facility, and in his off time joined the department’s Baker-to-Vegas running team. He worked as a senior training officer and a detective at the Century Station and as a K-9 handler at the Special Enforcement Bureau.

Lemus was known for his mentorship and his arrests of career criminals, department officials said. He joined the Arson and Explosive unit last year.

He is survived by his wife, Sheriff’s Department Detective Nancy Lemus, and three daughters.

Detective Osborn joined the department in 1992, and after serving as the Men’s Central Jail, moved to the Industry Station, where he rose to the rank of detective. Over more than a decade as an investigator, Osborn handled upward of a hundred cases a year and gained recognition for his skill at recovering stolen vehicles.

Osborn moved to the department’s training bureau in 2016, where he worked as an emergency vehicle operations instructor. But his love for investigations drew him back into the detective ranks, officials said, and he joined the Special Enforcement Bureau and the arson and explosives unit in 2019. He was considered a leader among his peers in the unit, officials said, often handling cases that involved damage to expensive properties or the loss of life.

He is survived by his wife, Detective Shannon Rincon, four sons, and two daughters.

The blast was reported at 7:25 a.m. Friday when the detectives were moving ordnance in the training center’s parking lot.

Luna would not confirm reports suggesting the explosion involved unexploded ordnance that had been seized Thursday. However, on Friday, Santa Monica police, along with county and federal investigators, were seen searching an apartment complex in the 800 block of Bay Street, near Lincoln Boulevard.

A resident of that complex told KTLA5 that police and sheriff’s officials had been at the building Thursday to retrieve some old grenades that a tenant found in a storage unit, apparently left behind by a previous tenant. The search Friday afternoon prompted an evacuation of at least part of that apartment complex as investigators swept the property for any additional potentially dangerous materials.

The sheriff’s department is investigating the apartment complex in connection with the explosion, department spokesperson Nicole Nishida told The L.A. Times.

U.S. Attorney General Pam Bondi was among the federal officials to comment Saturday, saying on X that she had spoken with both Luna and U.S. Attorney in Los Angeles Bill Essayli. She also confirmed that the FBI and Bureau of Alcohol, Tobacco, Firearms and Explosives were assisting with the investigation.

“Our federal agents are at the scene and we are working to learn more,” she wrote. “Please pray for the families of the sheriff’s deputies killed.”

The ATF announced it has activated its National Response Team to deploy to the scene of the explosion. The team consists of special agents, certified fire investigators, a forensic chemist, intelligence research specialist, certified explosives specialist, law enforcement training specialist, fire protection engineer, electrical engineer and an accelerant detection dog with handler, according to the bureau.

Gov. Gavin Newsom said he was briefed on the blast and that the Governor’s Office of Emergency Services was in contact with the sheriff’s department and closely monitoring the situation, offering “full state assistance.”

Newsom’s office also announced the state had deployed investigative personnel from the Office of the State Fire Marshal at the request of the ATF.

Information about memorial services will be announced in the coming days, officials said.

City News Service contributed to this report.