A preliminary investigation into last month’s fatal car crash involving a Tesla vehicle has raised doubts that the car’s autopilot feature played a role but stopped short of stating who or what was ultimately responsible for the crash.
The report from the National Transportation Safety Board, released Monday, says that home security camera footage shows that the owner of a Tesla got into the driver's seat of the car shortly before the deadly crash in suburban Houston.
But the report doesn't explain the mystery of why authorities found no one behind the wheel of the car, which burst into flames after crashing about 550 feet from the owner's home. Nor does it conclusively say whether Tesla's "Autopilot" partially automated driver-assist system was operating at the time of the crash, although it appears unlikely.
The NTSB said it's still investigating all aspects of the crash. An onboard data storage device in the console, however, was destroyed by fire. A computer that records air bag and seat belt status as well as speed and acceleration was damaged and is being examined at an NTSB lab.
The NTSB said it tested a different Tesla vehicle on the same road, and the Autopilot driver-assist system could not be fully used. Investigators could not get the system's automated steering system to work but were able to use Traffic Aware Cruise Control.
Autopilot needs both the cruise control and the automatic steering to function. Traffic Aware Cruise Control can keep the car a safe distance from vehicles in front of it, while autosteer keeps it in its own lane. The report said the road also did not have lane lines, which could have been why the automatic steering wouldn't work.
"The NTSB continues to collect data to analyze the crash dynamics, postmortem toxicology test results, seat belt use, occupant egress and electric vehicle fires," the agency said in its report. "All aspects of the crash remain under investigation as the NTSB determines the probable cause."
The agency says it intends to issue safety recommendations to prevent similar crashes.
The April 17 crash happened after 9 p.m. on a two-lane residential road in Spring, Texas. Both the 59-year-old vehicle owner and the 69-year-old passenger were killed.
The NTSB report said the 2019 Model S went off the road on a curve, drove over a curb, hit a drainage culvert, a raised manhole and a tree.
The crash damaged the high-voltage lithium-ion battery, where the fire began.
Local authorities said one man was found in the front passenger seat, while another was in the back. It remains unclear exactly how fast the car was going, but county officials said it was a high speed.
The NTSB, which has no regulatory authority and can only make recommendations, said it's working with the National Highway Traffic Safety Administration on the probe. NHTSA has the power to make vehicle safety regulations. The federal probe is running at the same time as a parallel investigation by local authorities, the NTSB said.
The Texas crash raised questions about whether Autopilot was working at the time, and whether Tesla does enough to make sure drivers are engaged. The company says in owner's manuals and on its website that Autopilot is a driver-assist system and drivers must be ready to act at any time.
The Associated Press contributed to this report.