DETROIT (AP) – A government investigation has found that a design flaw in Tesla’s Autopilot semi-autonomous driving system and driver inattention combined to cause a Model S electric car to slam into a firetruck parked along a California freeway.

The National Transportation Safety Board determined that the driver was overly reliant on the system and that Autopilot’s design let him disengage from driving.

The agency released a brief report Wednesday that outlined the probable cause of the January 2018 crash on a highway in Culver City.

The findings raise questions about the effectiveness of the Autopilot system, which was engaged but failed to take action in the Culver City crash and three others in which drivers were killed since 2016.

No one was hurt in the Culver City crash involving a Model S Tesla.

Latest News Headlines: