An anonymous reader quotes a report from CNBC: The U.S. National Highway Traffic Safety Administration said on Thursday it is opening a preliminary investigation into 25,000 Tesla Motors Model S cars after a fatal crash involving a vehicle using the "Autopilot" mode. The agency said the crash came in a 2015 Model S operating with automated driving systems engaged, and "calls for an examination of the design and performance of any driving aids in use at the time of the crash." It is the first step before the agency could seek to order a recall if it believed the vehicles were unsafe. Tesla said Thursday the death was "the first known fatality in just over 130 million miles where Autopilot was activated," while a fatality happens once every 60 million miles worldwide. The electric automaker said it "informed NHTSA about the incident immediately after it occurred." The May crash occurred when a tractor trailer drove across a divided highway, where a Tesla in autopilot mode was driving. The Model S passed under the tractor trailer, and the bottom of the trailer hit the Tesla vehicle's windshield. Tesla quietly settled a lawsuit with a Model X owner who claims his car's doors would open and close unpredictably, smashing into his wife and other cars, and that the Model X's Auto-Pilot feature poses a danger in the rain.