A bus rear-ended a car on eastbound Interstate 580 near Tracy, killing an off-duty Bay Area law enforcement officer, according to the California Highway Patrol.
The bus was carrying Tesla employees en route to Stockton in a bus contracted by their company, news reports said.
The accident happened on the Altamont Pass.
KCRA 3 reported that the CHP would not say which department the deceased officer worked for. His identity has not been released.
Three lanes were blocked on I-580 due to the accident. It is unclear when the lanes will reopen.