The widow of a Los Angeles County Sheriff's Department (LASD) deputy has filed a lawsuit against the city of Santa Monica, alleging negligence led to her husband's death in a grenade explosion last year. Shannon Rincon claims the city did not provide sufficient information about the military-style weapon before it detonated, killing her husband, Deputy William Osborn, and two colleagues.

Osborn, 58, died alongside detectives Joshua Kelley-Eklund, 41, and Victor Lemus, 40, on July 18, 2025, when an explosive device detonated at an LASD training facility in East Los Angeles. The grenade had been recovered from an apartment complex in Santa Monica the day prior, at the request of the Santa Monica Police Department, according to the lawsuit.

The three deputies, who were assigned to the LASD Special Enforcement Bureau’s Arson Explosives Detail, were inspecting the devices when the explosion occurred. The lawsuit states that city personnel characterized the devices as "inactive, inert, and safe to transport" despite lacking a proper basis for this assessment. It further alleges that "Had City of Santa Monica personnel had reasonably investigated, the devices would have been treated as live and unstable; and the fatal explosion would have been avoided."

The blast was powerful enough to shatter windows and trigger car alarms up to 100 feet away. The Los Angeles County Medical Examiner’s office determined Osborn’s cause of death was multiple blast injuries.

This is not the first legal action stemming from the incident. Earlier this year, Nancy Lemus, the widow of Deputy Victor Lemus, filed a separate lawsuit. Her suit names Los Angeles County, the LASD, Sheriff Robert Luna, and Commander Thomas Giandomenico as defendants. It also alleges that Lemus was not adequately trained to handle live explosive devices and claims Giandomenico photographed Lemus's remains after the explosion and shared them inappropriately.

Sheriff Luna was aware of the photos but did not confiscate the cellphone, according to the lawsuit filed by Lemus's widow. Luna had spoken at Lemus’s funeral, which was the last of the three deputies to be laid to rest.

The three deceased officers had a combined 74 years of service with the department and collectively left behind 16 children.

The LASD and the city of Santa Monica have been contacted for comment regarding the lawsuits.