California Department of Motor Vehicles announced that Cruise will reduce its robotaxi fleet in San Francisco by 50%.

Earlier this week, Cruise autonomous vehicles were involved in several crashes in San Francisco, including one on Thursday night when a self-driving car collided with a fire truck.

Cruise, a GM subsidiary, started offering a paid robotaxi service in San Francisco after it and Alphabet’s Waymo received permission to expand driverless operations and carry paying passengers 24 hours a day. At the moment, Cruise has a waitlist.

Also highlighted is San Francisco’s growing debate over driverless cars. Their opponents say they are dangerous and interfere with firefighters and other first responders, while defenders say they are innovative and will make getting around the city cheaper and easier.

In a statement, a DMV spokesperson said the department is investigating recent incidents involving Cruise vehicles. According to the DMV, Cruise has been contacted by law enforcement officials and asked to reduce its active fleet of operating vehicles by 50% immediately until the investigation is complete and Cruise takes appropriate corrective actions to improve road safety.

During the day, Cruise will have no more than 50 autonomous vehicles operating and no more than 150 during the evening, according to the DMV. On the night shift, Cruise operated 300 cars, while on the day shift, it operated 100.

It wasn’t possible to reach a Cruise spokesperson outside of business hours for a comment.

Several factors contributed to the accident with Cruise’s vehicle and firetruck on Thursday, according to Cruise’s San Francisco general manager Greg Dietrerich, who wrote a blog post on Friday night. These included buildings at the intersection that were hard to see. According to him, the firetruck was also going through a red light in the wrong lane.

Dietrerich wrote, “We will continue to work with regulators and city departments to reduce the likelihood of incidents like these recurring.”

Several incidents involving Cruise’s fleet drew media attention over the past week. Additionally, a Cruise vehicle got stuck in concrete, and an autonomous vehicle with a passenger was hit by a driver. According to Cruise, the other driver ran a red light in that incident. A number of Cruise vehicles stalled outside an outdoor music festival last weekend, slowing traffic.