Authorities say a Tesla driver, who said he thought his car was in Autopilot mode, crashed into the back of a firetruck in San Jose.
The California Highway Patrol says the Tesla rear-ended a fire engine that was stopped with its emergency lights activated along US-101 around 1 a.m. Saturday.
The 37-year-old driver, Michael Tran, told officers, "I think I had auto-pilot on."
Tran was later arrested on suspicion of drunken driving. It wasn't immediately clear if he had an attorney.
The San Francisco Chronicle reports that the two firefighters in the firetruck were not injured. The newspaper says Tran and a female passenger in the Tesla were taken to San Jose Regional Medical Center with minor injuries.
Tesla's semi-autonomous Autopilot mode has come under scrutiny following other recent crashes. The carmaker says the function is not designed to avoid a collision and warns drivers not to rely on it entirely.
It was unclear whether Autopilot was activated. Tesla says in a statement that it "has not yet received any data from the car, but we are working to establish the facts of the incident."