Joshua Brown’s Tesla warned him seven times to put his hands back on the wheel before he plowed into a truck. A National Transportation Safety Board report on the deadly crash also found that Brown had his hands on the wheel of the Tesla Model S for 25 seconds out of 37 minutes that the car was on autopilot.  The crash, near Gainesville, Florida, in May 2016, drew attention because of the questions it raised about the safety of self-driving cars.