TRACY, Calif. >> An off-duty Alameda County Sheriff’s deputy was killed Friday when a bus carrying Tesla employees crashed into his stalled car on a highway east of San Francisco.

Deputy Sroeuy Khin was killed after working a 12-hour shift at Santa Rita jail and a day before his 51st birthday, Alameda County Sheriff Gregory Ahern said.

The collision occurred when the deputy’s Volkswagen was stopped on Interstate 580’s Altamont Pass in Tracy, about 75 miles (120 kilometers) east of San Francisco, and was rear-ended by the bus carrying 51 Tesla employees, the California Highway Patrol said. One bus passenger had minor injuries.

The bus driver told CHP officers he didn’t see Khin’s car because the sun was in his eyes.

A 10-year veteran of the department, Khin leaves behind a wife and four children, Ahern said. “He’s one of our hardest working employees,” he said.

Khin is the second Alameda County Sheriff’s deputy to be killed this year. In February, deputy Mike Foley was hit by a prison bus while walking near Santa Rita jail. He later died in a hospital from head trauma.