A Tesla driver was killed in a collision in Florida with a tractor trailer while the vehicle was in “Autopilot” mode, the car maker announced Thursday.

It is the first known fatality in more than 130 million miles driven with autopilot activated, Tesla said in a statement which also expressed condolences to the driver’s family.

The National Highway Traffic Safety Administration said it was investigating the fatality to see if the autopilot system was to blame. But Tesla acknowledged that the accident might have been the fault of the computer.

“NHTSA’s Office of Defects Investigation will examine the design and performance of the automated driving systems in use at the time of the crash,” administration spokesman Bryan Thomas said in a statement. “During the Preliminary Evaluation, NHTSA will gather additional data regarding this incident and other information regarding the automated driving systems.”

The crash occurred May 7 when Joshua David Brown, 40, of Canton, Ohio, was behind the wheel of his black 2015 Model S Tesla, while in Autopilot mode on Route-27 in Williston, Florida, and hit the side of a tractor trailer that was crossing the road to make a turn.

“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 entitled “A Tragic Loss.”

The Model S passed under the trailer, crushing the top of the car and the windshield. “Had the Model S impacted the front or rear of the trailer, even at high speed, its advanced crash safety system would likely have prevented serious injury as it has in numerous other similar incidents,” Tesla said.