Kyle Vogt has resigned as CEO of Cruise, General Motors’ autonomous vehicle unit, as questions build about the safety of self- driving cars.

Vogt’s decision to step down, announced late Sunday, follows a recent recall of all 950 Cruise vehicles to update software after one of them dragged a pedestrian to the side of a San Francisco street in early October. The California Department of Motor Vehicles revoked the license for Cruise.

The company earlier announced it had paused operations for a review by independent experts.

Problems at Cruise, which won approval to transport fare-paying passengers last year, could slow the deployment of fully autonomous vehicles.