Two fatal crashes involving Ford's Blue Cruise partially automated driving system are now subjects of a National Highway Traffic Safety Administration investigation of the crashes, both involving Mustang Mach-E electric vehicles on freeways in nighttime lighting conditions, the agency said Monday. The agency's initial investigation of the crashes, which killed three people, determined that Blue Cruise was in use just before the collisions. The agency says the investigation will evaluate how Blue Cruise performs driving tasks as well as its camera based driver monitoring system. Ford said Monday it is working with NHTSA to support the investigation, reports the AP. The National Transportation Safety Board, which already is investigating a Feb. 24 San Antonio crash, determined in a preliminary report that it was operating on Blue Cruise.