Virginia authorities have determined that a Tesla was operating on its Autopilot system and was speeding in the moments leading to a crash with a crossing tractor-trailer last July that killed the Tesla driver. The death of Pablo Teodoro III, 57, is the third since 2016 in which a Tesla that was using Autopilot ran underneath a crossing tractor-trailer, raising questions about the partially automated system's safety and where it should be allowed to operate. The crash south of Washington remains under investigation by the U.S. National Highway Traffic Safety Administration, which sent investigators to Virginia last summer and began a broader probe of Autopilot more than two years ago.