The National Transport Safety Board on Tuesday determined the cause behind the 2018 fatal crash involving a Tesla Inc. (NASDAQ:TSLA) vehicle to be the limitations of the autopilot feature combined with driver negligence.

What Happened

Apple Inc. (NASDAQ:AAPL) engineer Walter Huang who died in the crash, was likely distracted playing a game on his smartphone at the time of the crash, the NTSB said.

Huang's overreliance on Tesla's autopilot was also a contributing factor, the investigative agency concluded in a public meeting on Tuesday.

The agency found Tesla's monitoring of driver engagement in the task to be "ineffective," as it deemed that autopilot can't excuse a driver from keeping their attention on the wheel.

"This tragic crash clearly demonstrates the limitations of advanced driver assistance systems available to consumers today," NTSB Chairman Robert Sumwalt said in a statement. "There is not a vehicle currently available to US consumers that is self-driving. Period."

What's Next

NTSB made nine recommendations to Tesla, the National Highway Traffic Safety Administration, transportation agencies, and lawmakers to avoid future crashes involving automated driving assistance.

The federal agency said the Tesla autopilot needs "evaluation" to see if its "operating limitations," "foreseeability of misuse," or the "ability to operate vehicles outside the intended operational design domain" can pose an unreasonable risk to safety.

The NTSB only has the authority to make recommendations, but can't oversee if they are implemented.

The federal agency had made similar recommendations to Tesla two years ago following a 2017 crash, but the automaker is yet to act on any of them, the Associated Press noted.

Sumwalt particularly emphasized the need for drivers to not be distracted by smartphones. "The lessons learned from this investigation are as much about people as they are about the limitations of emerging technologies," he said.

"If we don't get on the top of it, it's going to be a coronavirus," Sumwalt added, according to the Associated Press.

Price Action

Tesla's shares closed 4% lower at $799.91 on Tuesday. The stock dipped further 1.11% lower in the after-hours session at $791 per share.