In the last seconds leading to the crash, the driver's hands were not detected on the steering wheel and the vehicle began to accelerate to 71 mph.
The National Transportation Safety Board has released its preliminary report on the recent fatal Tesla Autopilot accident involving a Model X that struck a highway divider in California.
The report mostly summarizes information already known about the accident, confirming that Autopilot was engaged at the time and the driver's hands were not detected on the wheel in the six seconds prior to the crash.
"At 3 seconds prior to the crash and up to the time of impact with the crash attenuator, the Tesla's speed increased from 62 to 70.8 mph, with no precrash braking or evasive steering movement detected," the NTSB found.
The agency also focused on the emergency response, including attempts to extinguish the battery fire that ignited after bystanders removed the victim from the wreckage. Notably, the battery reignited five days after the vehicle had been towed to an impound lot.
"All aspects of the crash remain under investigation as the NTSB determines the probable cause, with the intent of issuing safety recommendations to prevent similar crashes," the report added.