The contact owns a 1995 N/A GMC Sierra 1500. The contact stated that after parking, turning the vehicle off, and exiting, the vehicle suddenly rolled forward, down a slight incline, and crashed into another parked vehicle. The cause of the failure was not determined. The manufacturer and local dealer were not contacted regarding the failure. In addition, while making a left turn into an intersection, a second vehicle crashed into the front of the vehicle. During the crash, no air bags deployed. The contact sustained injuries to both the shoulder and the chest. No medical treatment was required. A police report was filed at the scene. The cause of the failure was not determined. No further information was available. The VIN was not available. The failure mileage was 4,000.