Investigators from the National Traffic Safety Board will examine a crash that happened Monday, when a Tesla Model S Tesla plowed into the back of a fire truck on a freeway near Culver City, California.

The field investigation will focus on both driver and vehicle factors, the NTSB sold CNBC Tuesday. The agents will likely arrive at the scene on Wednesday, said NTSB spokesman Chris O’Neil.

No injuries were reported in the crash on Interstate 405 in Culver City in Los Angeles County.

The Culver City Firefighters Association Local 1927 union chapter tweeted out a picture of the crash on Monday afternoon. The driver said the car was on Tesla’s Autopilot driver assistance system.

The firetruck was on the freeway helping after a motorcycle accident, the union said in an Instagram post. The post said there were no injuries.

The outcome could have been much worse if firefighters had been standing at the back of the truck, Battalion Chief Ken Powell told the San Jose Mercury News.

Tesla shares were up slightly Tuesday morning.

Tesla’s Autopilot system has raised some controversy and has been involved in a few accidents, including the May 2016 fatal crash in Florida of a driver using the system. That led to investigations by the National Highway Traffic Safety Administration and the National Traffic Safety Board.

The NHTSA investigation found no defects in the Autopilot system that might have contributed that accident. NTSB investigators said the accident resulted from a combination of factors, including the limitations of the system as well as the actions of both the Tesla driver and the driver of the semitrailer the car crashed into.

Tesla tells drivers in its manual that the system is only meant to be used in certain conditions, and the system itself takes certain measures to prevent misuse. For example, it issues warnings and ultimately shuts off Autopilot if drivers remove their hands from the steering wheel.