Washington (AP) — The National Transportation Safety Board says the driver of a Tesla SUV who died in a Silicon Valley crash two years ago was playing a video game on his smartphone at the time.

Chairman Robert Sumwalt said at the start of a hearing Tuesday that partially automated driving systems like Tesla’s Autopilot cannot drive themselves. Yet he says drivers continue to use them without paying attention. He says the board made recommendations to six automakers in 2017 to stop the problem and only Tesla has failed to respond.

The board will determine a cause of the crash at the hearing and make recommendations to prevent it from happening again.