Fatal Tesla crash last month in Calif. probed by NHTSA

The National Highway Traffic Safety Administration (NHTSA) said on Wednesday it is opening a new special investigation into a February fatal crash in California involving a Tesla Model S where an advanced driver assistance system was suspected of having been used.

The agency is investigating the crash of a 2014 model year Tesla involving a fire truck in Contra Costa County, Calif. The fire department said a Tesla struck one of its fire trucks and the Tesla driver was pronounced dead at the scene.

Tesla did not immediately comment.

In December, NHTSA said it had opened two new special investigations into crashes involving Tesla vehicles where advanced driver assistance systems are suspected to have been in use.

Since 2016, NHTSA has opened more than three dozen Tesla special crash investigations where advanced driver assistance systems such as driver assistance system Autopilot were suspected of being used with 20 crash deaths reported.

NHTSA typically opens more than 100 special crash investigations annually into emerging technologies and other potential auto safety issues that have, for instance, previously helped to develop safety rules on air bags.

In June, NHTSA upgraded to an engineering analysis its defect probe into 830,000 Tesla vehicles with driver assistance system Autopilot and involving crashes with parked emergency vehicles including fire trucks. That step was necessary before the agency could demand a recall.

NHTSA is reviewing whether Tesla vehicles adequately ensure drivers are paying attention. Previously, the agency said evidence suggested drivers in most crashes under review had complied with Tesla's alert strategy that seeks to compel driver attention, raising questions about its effectiveness.