NEW YORK (TheStreet) -- Tesla Motors (TSLA) - Get Report stock is down 2.96% to $206 in after-hours trading on Thursday after the company confirmed that the National Highway Traffic Safety Administration opened a preliminary evaluation into the Model S autopilot function following a fatal crash.

The electric automaker said the fatality was the first in more than 130 million miles where the autopilot function was activated.

"It is important to emphasize that the NHTSA action is simply a preliminary evaluation to determine whether the system worked according to expectations," Tesla said in a blog post.

Tesla explained that a tractor trailer drove perpendicular to the vehicle involved. The autopilot and the driver did not hit the brakes because the bright white side of the trailer made it hard to see.

"It is important to note that Tesla disables Autopilot by default and requires explicit acknowledgement that the system is new technology and still in a public beta phase before it can be enabled," Tesla explained, adding that the vehicle reminds drivers to be attentive when autopilot is engaged.

Separately, Tesla Motors has a "sell" rating and a letter grade of D+ at TheStreet Ratings because of the company's deteriorating net income, generally high debt management risk, disappointing return on equity, weak operating cash flow and generally disappointing stock performance.

You can view the full analysis from the report here: TSLA

TheStreet Ratings objectively rated this stock according to its "risk-adjusted" total return prospect over a 12-month investment horizon. Not based on the news in any given day, the rating may differ from Jim Cramer's view or that of this article's author.

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