As robotaxis becomes more mainstream and spreads across American cities, accidents do happen.

Unfortunately, we are starting to see some. A Waymo robotaxi hit a child near an elementary school in Santa Monica on January 23. Luckily, the child’s injuries were minor.

The National Highway Traffic Safety Administration (NHTSA) said Wednesday that the incident occurred at normal school dismissal time, roughly two blocks from the school. According to the administration, there are other children in the area with a crossing guard, and many cars double-parked on the side of the road.

The boy reportedly ran across the road to school from behind a parked SUV and was hit by the robotaxi, which had no safety operator inside the vehicle.

NHTSA’s Office of Defects Investigation said it has opened an investigation to determine whether Waymo “exercised reasonable precautions given, among other things, its proximity to an elementary school during drop off times, and the presence of young pedestrians and other potentially vulnerable road users.” The investigation will also examine the car’s automated driving system and its intended behavior in school zones.

“This event shows the critical value of our safety systems,” Waymo said in a blog post on Wednesday about the incident. “We remain committed to improving road safety where we operate as we continue our mission to be the world’s most trusted driver.”

According to Waymo, the vehicle’s technology detected the child immediately after they began running from behind the SUV, causing the vehicle to brake hard and reduce its speed from approximately 17 miles per hour to less than 6 miles per hour before contact. In contrast, Waymo said that based on its peer-reviewed model, an attentive human driver in the same situation would have hit the child at approximately 14 miles per hour.

According to the company, the boy stood up immediately after the crash and was able to walk to the sidewalk. The vehicle then called 911 and remained in the area until law enforcement gave it permission to leave. Waymo also said it voluntarily contacted NHTSA the same day.

The accident comes just a month after NHTSA sent Waymo a LETTERS announced a preliminary investigation following multiple reports that Waymo vehicles failed to wait for school buses with flashing lights and drove around them. The investigation focused on whether the automated systems in the vehicles could comply with traffic laws related to school buses.

In November, Waymo issued a recall affecting more than 3,000 vehicles to address the issue. However, incidents reportedly continued thereafter. The Austin Independent School District told CBS News in December it was aware of at least 20 such incidents.

The reviews come as Waymo continues to expand its robotaxi service to more cities. The company operating now in the San Francisco Bay Area, Phoenix, Los Angeles, Austin, Atlanta, and, most recently, Miami. Waymo also announced plans to expand into additional markets, including Baltimore, St. Louisand Philadelphia.