EXPERIENCED DRIVER ATTEMPTED TO MOVE TRUCK SLOWLY. TRUCK ACCELERATED AND WHILE ATTEMPTING TO BRAKE, DRIVER COULD NOT DO SO. THIS TRANSPIRED FROM A PARKED POSITION AND ATTEMPTING TO GO FORWARD APPROX. A FOOT. SPEED HAD SUCH A VELOCITY THAT DRIVER HIT HIS HEAD ON ROOF OF TRUCK. THE TRUCK ACCELERATOR WAS STUCK AND THE TRUCK WENT OVER A LOW BEARING WALL. TRUCK WAS PARKED IN A DRIVEWAY. COMPLAINT WAS FILED WITH GM IN MAY 2018 WITH NO FURTHER CONTACT FROM GM AFTER INVESTIGATION HAS BEEN CONCLUDED. THERE IS A RECALL ON THIS TRUCK 16V-797 THE STICKER ON TRUCK FOR VIN STATES NOV. 2018. GM HAS NOT RESPONDED SINCE THE INVESTIGATION. *DT UPDATED 11/02/18*JB