The wreck involved a Tesla Model X in Pennsylvania.
According to the Detroit Free Press, the driver in that crash told police that he was using Tesla's assisted driving feature, which helps motorists steer, stay in lanes and drive at the speed of traffic. The vehicle reportedly hit a freeway guardrail and struck the center median before flipping onto its roof.
Last week, the agency disclosed a separate investigation into a fatal crash in Florida in May that involved a Tesla Model S. The driver in that crash was using Tesla's assisted driving feature at the time of the incident.
The electric car manufacturer said Wednesday in a prepared statement that it received a message from the vehicle's computer July 1 indicating a crash had occurred, but more detailed logs were never transmitted.
"We have no data at this point to indicate that Autopilot was engaged or not engaged," a Tesla spokesperson said in a statement. "This is consistent with the nature of the damage reported in the press, which can cause the antenna to fail."
The company said it has been unable to reach the driver.
"It is not possible to learn more without access to the vehicle's onboard logs."
NHTSA said in a statement that it is collecting information from the Pennsylvania State Police, Tesla and the driver of the Model X to determine whether automated functions were in use at the time of the crash.
The driver involved in the crash, Michigan art gallery owner Albert Scaglione, declined to comment.
2:24 p.m. Thursday, July 7: This article was updated with additional information.