(Newser) – Three crashes involving Teslas that killed three people have increased scrutiny of the company's Autopilot driving system just months before CEO Elon Musk plans to put fully self-driving cars on the road. On Sunday, a Tesla Model S sedan left a freeway in Gardena, California, at a high speed, ran a red light and struck a Honda Civic, killing two people inside, police said. On the same day, the AP reports, a Model 3 hit a parked firetruck on an Indiana freeway, killing a passenger in the Tesla. And on Dec. 7, a Model 3 struck a police cruiser on a Connecticut highway, though no one was hurt. The special crash investigation unit of the National Highway Traffic Safety Administration is looking into the California crash. The agency hasn't decided whether the unit will review the Indiana one. In both cases, authorities have yet to determine whether Tesla's Autopilot system was being used.

NHTSA also is investigating the Connecticut crash, in which the driver told police the car was operating on Autopilot, a Tesla system designed to keep a car in its lane and a safe distance from other vehicles. Tesla has said repeatedly that Autopilot is designed only to assist drivers, who must still pay attention and be ready to intervene at all times. The company contends that Teslas with Autopilot are safer than vehicles without it, but cautions that the system does not prevent all crashes. Even so, experts and safety advocates say a string of crashes raises questions about whether drivers are too reliant on Tesla's technology. Some have said it's past time for NHTSA to stop investigating and to take action, such as forcing Tesla to make sure drivers pay attention when the system is being used. "At some point, the question becomes: How much evidence is needed to determine that the way this technology is being used is unsafe?" one safety advocate said.

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