The National Highway Traffic Safety Administration said today it has opened a formal investigation into the safety of the Tesla Model S electric car following two reports of battery fires after striking roadway debris.
The agency said its safety investigation was prompted by recent "undercarriage strikes" in Washington state and Tennessee. In both cases, fires resulted after the cars both ran over debris on the road that pierced the battery compartment. After news of the probe broke, Tesla shares fell to $116 in pre-market trading but climbed back once the market opened. Tesla shares were trading up $5.87, or 4.7%, to $127.43 in the first hour of trading.
Early Tuesday before NHTSA's announcement, Tesla CEO Elon Musk announced that he taking three steps as a result of the fires, but added that he stands behind their safety.