A Long Beach Police Department K-9 officer appears to have died from heat while alone in a department-issued vehicle, according to the LBPD.

The dog, Ozzy, was found dead by his handler around 3:40 p.m. on Aug. 14, LBPD spokeswoman Shaunna Dandoy said.

“A local veterinarian examined Ozzy and the preliminary results determined the cause of death to be heat related,” Dandoy said.

Police said they are reviewing all the circumstances around Ozzy’s death, including “possible equipment or mechanical failures,” but they believe it was accidental.

Both Ozzy and his handler were off-duty at the time, according to the LBPD. Ozzy was in a department-issued vehicle equipped for K-9 officers, police said.

Part of that special equipment is a cooling system that’s not supposed to shut off unless it’s manually disabled, the LBPD said. In addition, handlers have apps on their phones that are supposed to alert them if their cars get too hot, according to an LBPD spokesperson.

“At this time, we believe this alert may not have been working,” police said.

While police try to figure out exactly what happened, K-9 handlers have been told to make sure the cooling systems in their cars are working before every shift, according to the department.

Ozzy, who was part Belgian Malinois and part German Shepherd, worked in drug investigations, according to an article in the Signal Tribune last year. Ozzy had been on the force more than five years, according to the article.

In a statement, police asked for respect for Ozzy’s handler and his family.

“Our department is mourning Ozzy’s loss as we would with any of our employees, our K-9’s are an indispensable part of our department, and we will continue to view them as partners,” the statement said in part.

Ozzy is not the only LBPD K-9 to die suddenly in the last few years. In 2016, the K-9 Credo was killed by friendly fire while officers were trying to detain a knife-wielding man named Barry Prak, who was also killed by the gunfire, according to authorities.

Editor’s note: This story was updated with more information from police Friday afternoon.