The first American killed by a self-driving car died when the Tesla he was operating on “autopilot” mistook a tractor trailer for a bright sky, the National Highway Traffic Safety Administration reported. The driver, identified as 40-year-old Josh Brown, was using his Tesla Model S’s built-in system in Florida in May when the truck made a left turn in front of him at a highway intersection without a traffic light. The car’s automatic braking system, which is designed to stop a vehicle before a collision, did not engage. “What we know is that the vehicle was on a divided highway with autopilot engaged when a tractor trailer drove across the highway perpendicular to the Model S,” Tesla said in a statement. “Neither autopilot nor the driver noticed the white side of the tractor trailer against a brightly lit sky, so the brake was not applied.” Brown served as a Navy SEAL for more than 10 years. Tesla’s statement described him as a man “who spent his life focused on innovation and the promise of technology and who believed strongly in Tesla’s mission.” He posted several videos of himself driving the car in autopilot mode. “The car’s doing it all itself,’’ he says, smiling as he takes his hands off the steering wheel.