Federal highway safety regulators are investigating the first deadly crash in a self-driving car.
Read: Mom Accused of Texting Seconds Before Deadly Crash Acquitted in Death of Daughter, 2 Nieces
Joshua Brown, a Navy SEAL, was driving his Tesla vehicle near Gainesville, Florida, when his car slammed into a tractor-trailer on May 7.
In a statement, Tesla 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."
One question hanging over Brown's death is why it just came to light. Tesla said it had notified federal officials immediately after the crash happened.
Read: Watch Granny Freak Out While Driving A Tesla on Autopilot
According to several reports, the truck driver said Brown was watching a Harry Potter movie when the crash occurred. But the truck driver told Inside Edition that never happened.
Brown, a thrill-seeker, loved the futuristic car's autopilot self-driving feature. He was such a fan that he posted several videos on YouTube of his travels in the car. He even gave it a nickname: "Tessy."
He had one close call with his Tesla. It avoided an accident when a truck pulled into his lane.
"Tessy did great," he said on his YouTube channel. "I am very impressed."
It was the last video he ever posted.
Telsa's founder, billionaire Elon Musk, tweeted, "Our condolences for the tragic loss."
Car safety expert Lauren Fix warmed of the self-driving technology. “It is not a toy, it is not a game,” she said.