The National Highway Traffic Safety Administration (NHTSA) has opened a preliminary evaluation into the way that Cruise’s autonomous vehicles interact with pedestrians. The action follows a widely publicized incident in which one of the company’s vehicles struck a pedestrian, who had first been hit by another driver.

The incident occurred on Monday, October 2, when a woman in San Francisco was hit by a vehicle with a human driver, and thrown into an adjacent lane, where she was struck again by a Cruise autonomous vehicle that could not stop in time. Authorities say they struggled to free the woman, who suffered life-threatening injuries, from under the second vehicle.

However, that was not the only incident NHTSA cited as a reason for opening the preliminary evaluation. The federal regulator said that it had received two relevant reports involving pedestrian injuries from Cruise (including the above-mentioned incident), and is aware of two additional incidents from videos posted online.

Read: Cruise Autonomous Car Runs Over Pedestrian That Had Just Been Hit By Another Driver

 Feds Open Investigation Into Cruise’s Autonomous Vehicles Over Pedestrian Safety

It claims that it has received reports of autonomous Cruise vehicles encroaching on pedestrians present or entering the roadway. It says that the vehicles may not exercise appropriate caution around pedestrians at crosswalks, and in proximity of the vehicle’s travel path.

NHTSA says that it has opened the preliminary evaluation to determine how big of an issue this is, and how severe a risk it may pose to pedestrian safety. While such an evaluation does not constitute a recall, it is the first step along the path to one. Cruise told Autonews that it is cooperating with NHTSA’s requests for information.

Earlier this year, Cruise initiated a recall campaign of its autonomous vehicles following a crash with a San Francisco bus. The AV became confused by the articulated vehicle as it left a bus stop, which the company says will no longer happen.

The company has also been investigated by state officials in California following a pair of crashes on August 17. One of the incidents involved the autonomous vehicle driving into a fire truck. That led to a recent flurry of updates from Cruise aimed at improving its interactions with emergency vehicles.

 Feds Open Investigation Into Cruise’s Autonomous Vehicles Over Pedestrian Safety