The National Highway Traffic Safety Administration (NHTSA) and the National Transportation Safety Board (NTSB) said they are sending teams to investigate a fatal crash in Florida on Friday involving a Tesla Inc car and a semi-trailer. The two agencies are investigating several crashes involving the use of Tesla’s driver assistance system Autopilot including a fatal crash in California in March 2018. NHTSA, the auto safety regulator, can demand a recall if it believes a defect poses an unreasonable risk, while the NTSB makes safety recommendations.