Federal regulators are investigating a fatal collision involving a Tesla that may have been operating on an automated driving system at the time.

The National Highway Traffic Safety Administration opened the probe into the July crash between a Tesla Model Y and a tractor-trailer in northern Virginia, according to news reports. The driver of the Tesla died in the accident after the car ran underneath the truck. The NHTSA suspects the Tesla was running on a partially automated driving system at the time.

The accident brings the number of NHTSA-probed crashes involving Teslas believed to be operating on driver-assistance systems to about three dozen, news reports said. The Associated Press said the wrecks have resulted in at least 17 deaths.

Automated or semiautomated driving systems have been controversial due to safety concerns. Last year, the NHTSA issued a new rule to protect automated-vehicle occupants’ safety, ensuring “standards keep pace with the development of automated driving and driver assistance systems.”

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