On Monday afternoon, the National Transportation Safety Board released a preliminary report for its investigation into a crash of a Tesla Model S that killed the driver and passenger in Texas earlier in April. The crash made headlines because no one was found in the driver’s seat, raising suspicions that Tesla’s Autopilot driver-assistance system was involved in the deaths. This now seems unlikely—the NTSB says that video footage shows the occupants getting into the front seats of the car shortly before the crash. Additionally, the NTSB was unable to engage a component of Autopilot on the stretch of road where the crash happened.
The crash occurred on April 17 in Spring, located in Harris County, Texas. According to the NTSB report, footage from the owner’s home security system shows that the driver and a passenger entered the car at the owner’s house. They then traveled approximately 550 feet (167 m) “before departing the road on a curve, driving over the curb, and hitting a drainage culvert, a raised manhole, and a tree.” At this point, the Tesla’s lithium-ion traction battery was damaged and caught fire.
The fire also destroyed the on-board storage of the Tesla’s infotainment system, but the NTSB says it recovered a fire-damaged restraint control module that can “record data associated with vehicle speed, belt status, acceleration, and airbag deployment.” This module has been taken to the NTSB’s recorder laboratory for further testing.
Although this specific Tesla Model S was equipped with Autopilot, the NTSB investigation so far suggests that the driver-assistance system was not active. NTSB investigators could activate the Traffic Aware Cruise Control component of Autopilot on the stretch of road in question, but they were unable to activate Autosteer.
The NTSB says it is continuing to collect data “to analyze the crash dynamics, postmortem toxicology test results, seat belt use, occupant egress, and electric vehicle fires.” As for why the driver was not found in his seat, one troubling possibility is that the front door was inoperable or obstructed and the driver died while trying to escape from the rear of the Model S. Unlike most cars, Tesla uses IP-based electronic door locks that fail if the car loses power (as it would have in this crash). In an emergency that cuts power to the car, the rear doors of a Model S can only be opened using a plastic tab found in the rear footwell.