A Google autonomous vehicle struck a bus in California on Valentine’s Day, according to an incident report (PDF) published by the California Department of Motor Vehicles (DMV) on Monday. Google Automotive, the branch of Alphabet that handles self-driving car research, filed the incident report in accordance with California law.

No one was hurt, Google says.

According to the report, the vehicle was in autonomous mode and in the far right lane of a main thoroughfare in the California city of Mountain View. As it approached a red light, the car automatically signaled that it would make a right turn. Cars in the same lane ahead of the autonomous vehicle were waiting at the red light to proceed straight, so the autonomous vehicle got to the right of the lane to pass those other cars, but it sensed some sandbags around a storm drain in the road, and it stopped.

As the light turned green, the autonomous vehicle tried to drive back to the center of the lane to get around the sandbags. The autonomous vehicle’s operator saw a bus approaching in the left-hand mirror “but believed the bus would stop or slow to allow the Google AV [autonomous vehicle] to continue,” the report said.

“Approximately three seconds later, as the Google AV was reentering the center of the lane it made contact with the side of the bus,” the report continued. “The Google AV was operating in autonomous mode and traveling at less than 2mph, and the bus was traveling at about 15mph at the time of contact.”

The autonomous vehicle was a Lexus that Google had tricked out with sensors. The car suffered a damaged left front fender and left wheel, as well as a broken sensor on the driver’s side door.

Google's self-driving cars have been in the works for years, but it wasn't until 2014 that the California DMV said it would create rules to allow autonomous vehicles to be tested on the state's public roads. Part of that privilege comes with the requirement to submit accident reports regularly to the DMV, which the department then makes public. Google has reported a number of minor crashes involving autonomous cars in the past year, but a recent study of the crash data published by the DMV showed that most of the crashes occurred when human drivers hit robot drivers, rather than the other way around.