Federal transportation officials have opened a preliminary evaluation of the "autopilot" system on some Tesla vehicles after a deadly crash involving a car using the system.
The May 7 crash in Williston, Florida, was the first fatal crash involving Tesla's autopilot system, which allows the Tesla Model S to steer itself, the National Highway Traffic Safety Administration and the automaker said.
The deadly crash occurred after a tractor-trailer made a left turn in front of a 2015 Tesla Model S on a highway, the NHTSA said.
"Neither Autopilot nor the driver noticed the white side of the tractor trailer against a brightly lit sky, so the brake was not applied," Tesla said in a blog post Thursday. The company said it notified NHTSA after the crash occurred.
The driver who was killed was Joshua D. Brown, 40, of Canton, Ohio, according to the Florida Highway Patrol police report.
Tesla said the vehicle continued driving as the tractor-trailer turned, and went partially under the side of the trailer, and the bottom of the rig struck the car's windshield.
The company said the high ride height of the trailer and the "extremely rare circumstances of the impact" contributed to the deadly outcome.
"Our deepest condolences for the tragic loss," Tesla CEO Elon Musk said in a Tweet Thursday.
"We would like to extend our deepest sympathies to his family and friends," the company said.
The police report says the Tesla struck the trailer as it passed underneath, then the vehicle kept going and hit a fence and a utility pole.
The NHTSA's Office of Defects "will examine the design and performance of the automated driving systems in use at the time of the crash," the agency said in a statement.
The autopilot system is still in beta testing, and is turned off by default, Tesla said. The automaker said in a statement that drivers using the system are warned to keep their hands on the wheel and be ready to take over control.
"Autopilot is getting better all the time, but it is not perfect and still requires the driver to remain alert," Tesla said in a statement. Tesla said it was the first deadly crash in 130 million miles driven where autopilot was active.
The automaker said the NHTSA probe "is simply a preliminary evaluation to determine whether the system worked according to expectations." The agency also said the the evaluation should not be construed to mean regulators believe a defect either exists or doesn't exist.
The probe of the autopilot system affects 25,000 Tesla Model S vehicles, Reuters reported.