According to a police report obtained by CNN Business, a car wreck in California last month was caused by Full Self- Driving software.

According to the December 7th report obtained by CNN Business, the California Highway Patrol reviewed tunnel footage and found that aTesla made an unsafe lane change before abruptly slowing down, causing vehicles behind it to crash into one another.

The driver of the car said that the software malfunctioned and caused the car to slow down. A child was hospitalized after the Thanksgiving incident.

California Highway Patrol said in the Dec. 7 report that it could not confirm if “full self-driving” was active at the time of the crash. A highway patrol spokesperson told CNN Business on Wednesday that it would not determine if “full self-driving” was active, and Tesla would have that information.

Several other accidents, including one in Utah that killed a motorcyclist, are being investigated by the NHTSA.

The incidents implicate the advanced driver-assistance system (ADAS), autopilot, or the $15,000 Full Self-Driving (FSD) software package that performs many of the same tasks as autopilot on the streets. A Model Y vehicle was reported to have been involved in the first crash that claimed to have been caused by FSD.

The NHTSA reported earlier this year thatTesla was the top performer in crashes with ADAS. Critics say that the company is overstating the capabilities of its features and that the responsibility for safe operation of the vehicle falls on the driver.