A Tesla Model 3 rear-ended a Harley-Davidson in Utah, killing its rider, 34-year-old Landon Embry. 

The Tesla driver had merged into Embry's lane on Interstate 15 and struck the back of his motorcycle, sending him cascading off his bike.

The Tesla driver informed authorities he had Tesla's partially automated Autopilot driver assistance system turned on. 

The US National Highway Traffic Safety Administration (NHTSA) opened a special investigation into the crash -  the 39th the NHTSA has investigated since 2016, 30 of which involved Teslas. 

A few days earlier, a white Tesla Model Y rear-ended a Yamaha V-Star motorcycle in a high occupancy vehicle lane on a freeway outside Riverside, California, killing the rider.