MOUNTAIN VIEW (CBS SF) -- Federal transportation investigators Thursday cited speeding and a lack of driver control in a fatal Tesla crash and fire on Highway 101 in March.
According to a preliminary report from the National Transportation and Safety Board, at the time of the March 23rd crash that claimed the life of Walter Huang, the 2017 Tesla Model X was speeding, the "Autopilot" function was engaged and the driver's hands were not on the steering wheel for the last six seconds before the vehicle crashed into a previously damaged crash attenuator.
Using the black box features of the car, investigators said instruments showed that Huang had engaged the Autopilot function four times from the start of his 32-minute trip on the South Bay highway to the time of the crash.
The Autopilot function was engaged for the last 18 minutes and 55 seconds of Huang's drive that Friday morning.
During that time span, the vehicle provided two visual alerts and one auditory alert for the driver to place his hands on the steering wheel. The alerts
were made more than 15 minutes prior to the crash.
"For the last 6 seconds prior to the crash, the vehicle did not detect the driver's hands on the steering wheel," the report stated.
The report revealed that the Tesla's cruise control was set for 75 mph on the highway where the speed limit was 65. Investigators discovered that the Tesla was following a car until seconds before the crash. But the car either changed lanes or exited and once there were no vehicles in front of the Tesla, it began to accelerate.
"At 3 seconds prior to the crash and up to the time of impact with the crash attenuator, the Tesla's speed increased from 62 to 70.8 mph, with no pre-crash braking or evasive steering movement detected," the report stated.
The impact of the crash ripped the Tesla apart and it was struck by two other vehicles -- an Audi and a Mazda.
"During the collision sequence, the Tesla's 400-volt lithium-ion high-voltage battery was breached, and a post-crash fire ensued," the report stated.
Occupants of both the Audi and the Mazda quickly removed the gravely injured Huang from the Tesla before it burst into flames.
"The Mountain View Fire Department applied approximately 200 gallons of water and foam during a period of fewer than 10 minutes to extinguish fires involving the vehicle interior and the exposed portion of the high-voltage battery," according to the report. "\Technical experts from Tesla responded to the scene to assist in assessing high-voltage hazards and fire safety."
But the issues with the battery did not end there.
"Around 4:30 p.m. that afternoon, at the impound lot, the Tesla battery emanated smoke and audible venting," the report stated. "The battery was monitored with a thermal imaging camera, but no active fire operations were conducted. On March 28, 5 days after the crash, the battery reignited. The San Mateo Fire Department responded and extinguished the fire."
The NTSB said it was continuing to work with the California Highway Patrol and the California Department of Transportation to collect and analyze data, including all pertinent information relating to the vehicle operations and roadway configuration.
All aspects of the crash remain under investigation as the NTSB determines the probable cause.
Tesla did not comment on the NTSB report but referred to its earlier statement on the crash: "Tesla autopilot does not prevent all accidents -- such a standard would be impossible -- but it makes them much less likely to occur. It unequivocally makes the world safer for the vehicle occupants, pedestrians and cyclists."
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