According to a report from the National Transportation Safety Board, the Tesla driver Joshua Brown, who was killed last year while using the semi-autonomous Autopilot mode on his Model S, has been receiving several visual and audio warnings to take control of the vehicle before the accident. Brown kept his hands off the wheel ignoring the warnings which resulted in colliding with a truck on a Florida highway.

The new details of the 2015 Tesla Model S70D crash were revealed in more than 500 pages of records gathered as part of the NTSB’s investigation.

The May 7, 2016 crash brought widespread attention for being the first known fatal accident involving an autonomous car. Clearly, there was an inordinate amount of coverage on the fatal crash. Data from the vehicle’s system showed that the driver was operating the car using the automated control systems like Autosteer and traffic-aware cruise control longer than he should.

Brown was driving along a Florida highway in his 2015 Tesla Model S70D, when he collided with a tractor-trailer.

He was keeping his hands on the wheel for less than 30 seconds in a period of 37-minutes, but he should’ve maintained control of the vehicle instead of ignoring the warnings.

The report showed the Autopilot mode remained on during most of his trip but it gave him a clear visual warning “Hands Required Not Detected” 7 times before the accident.

Though the NHTSA didn’t find any evidence of a defect with Autopilot, the regulator’s report later stressed the necessity for drivers to pay attention while using Tesla’s Autopilot. The report confirmed earlier conclusions that the driver wasn’t watching a DVD.

Fatal Tesla Crash-Driver Ignored the Warnings To Take Control Back From Autopilot

The National Transportation Safety Board stated that any probable cause determinations related to the crash will be issued by the board at an undetermined date and no conclusions about the crash should be drawn from the file.

The board’s investigation is separate from the NHTSA’s probe, which earlier this year cleared Autopilot in the accident and didn’t order a recall. The accident file included a crash reconstruction report, , witness interviews and toxicology reports.