WASHINGTON (AP) — The first American death involving a car in self-driving mode presents a dilemma: How aggressively to embrace the potentially life-saving technology after a fatal crash. The driver’s history of speeding complicates the question.

The National Highway Traffic Safety Administration is investigating the design and performance of the Tesla Model S vehicle’s “Autopilot” system after announcing the death of a driver on Thursday. The system was engaged at the time of the crash, but that is only part of the story.

The driver, Joshua D. Brown, a 40-year-old technology company owner from Canton, Ohio, was so enamored of his sedan that he nicknamed it “Tessy” and praised the Autopilot’s safety benefits.

Brown published videos on Youtube of himself behind the wheel with the system active.

He was killed May 7 in Williston, Florida, when his car’s cameras failed to distinguish the white side of a turning tractor-trailer from a brightly lit sky and didn’t automatically activate the brakes, according to statements by the government and the automaker. Brown didn’t take control and brake, either.

Brown’s family said in a statement that it wanted to help the government and Tesla so that “information learned from this tragedy will trigger further innovation which enhances the safety of everyone on the roadways.”

His death comes at an awkward time for the U.S. government and car makers.

NHTSA Administrator Mark Rosekind was expected later this month to announce guidelines on self-driving cars for states and automakers.

The transition to the new technology could radically transform how people travel in the future.