June 8 (UPI) -- A Tesla SUV that crashed last spring while on autopilot accelerated just before crashing into a California freeway barrier and killing its driver, federal investigators have determined.
The March 23 crash killed Walter Huang who worked as an Apple engineer, as the Tesla Model X collided with a barrier on Highway 101 in Mountain View, Calif.
A preliminary report by the National Transportation Safety Board Thursday said data shows the SUV did not brake or try to steer around the barrier in the three seconds before the crash.
The report said the SUV was operating with "traffic-aware cruise control" before the crash.
The NTSB said the driver's hands were on the steering wheel for 34 seconds of the final minute, but left the wheel in the final six seconds. The agency also says it accelerated from 62 mph to 71 mph "with no pre-crash braking or evasive steering movement detected."
Tesla defended its autopilot mode and said in a statement a failure to repair the highway safety barrier exacerbated the crash.
"If you are driving a Tesla equipped with Autopilot hardware, you are 3.7 times less likely to be involved in a fatal accident ... The consequences of the public not using Autopilot, because of an inaccurate belief that it is less safe, would be extremely severe."
The company's autonomous driving mode has come under scrutiny lately after multiple crashes.
Last month, a Tesla Model S crashed into a stopped fire truck in Utah while operating in autopilot mode. The driver told police she was looking at her phone as the car slammed into the truck at about 60 mph.
The NTSB also is investigating a Tesla crash in Florida that killed two high school students last month.