A state investigation into an explosion of a grenade that killed three Los Angeles County sheriff’s bomb-squad detectives last year found a series of safety violations, including that some explosives had been left unattended.

The California Division of Occupational Safety and Health also found a failure to provide effective training and other citations, leading to more than $350,000 in fines against the Sheriff’s Department, according to a state report.

The Sheriff’s Department was appealing the citations, state officials said.

Among the violations, some of which were deemed “willful,” were that the department failed to ensure employees were using personal protective equipment when handling explosives, failed to establish and maintain effective methods to identify and evaluate hazards related to retrieving, transporting, storing and handling explosives, failed to maintain required documentation of safety training and complete and certify a written workplace hazard assessment for personal protective equipment.

The investigation started in the days after bomb-squad detectives Joshua Eklund-Kelley, William Osborn and Victor Lemus were killed in the blast on the morning of July 18, 2025, in the parking lot of the Biscailuz Center Training Academy, which is southwest of the 10 and 710 freeways.

The day before, Kelley-Eklund and Osborn had recovered a pair of grenades from a Santa Monica apartment complex and determined them to be inert. But at least one grenade was taken to the facility where it detonated.

“This tragedy underscores the responsibility employers have to anticipate hazards and take meaningful steps to protect workers, especially in high-risk operations involving explosive materials,” Cal/OSHA’s statement said. “We mourn the loss of these three sheriff’s deputies and extend our condolences to their families, coworkers, and first responders.”

The second grenade remained missing.

“The department is … working closely with county counsel to ensure that all information provided complies with legal requirements and does not compromise the integrity of the ongoing investigations,” the Sheriff’s Department said in a statement. “While some requested items have been provided, others are still in progress, and some do not exist.

“We share Cal/OSHA’s goal of ensuring the safety of our personnel and preventing a similar tragedy from occurring in the future,” the statement said. “And we are committed to providing them with the information they need to do their job, as well as continuously reviewing our own procedures to look for ways to improve. “

Changes have been made, the Sheriff’s Department said in it’s statement, with the agency consulting with the Los Angeles Police Department, the FBI and the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives:

Some updates include further standardizing department practices and processes to ensure organizational consistency, the introduction of new equipment and refining supervisory response protocols tailored to the nature of the call for service, as appropriate,” it said. “We are also in the process of updating our training manual and guidelines … to strengthen existing policing standards.”