I WAS VISITING SOMEONE AT A HOSPITAL. I ENTERED THE PARKING GARAGE AND PROCEEDED TO THE 2ND FLOOR. I BEGAN TO ENTER A PARKING SPACE SLOWLY WITH MY FOOT ON THE BRAKE PEDAL, WHEN THE CAR ACCELERATED AT A HIGH RATE OF SPEED ALL BY ITSELF FORWARD,SLAMMING INTO THE BARING WALL IN FRONT OF ME. AFTER CRASHING INTO THE WALL, THE ENGINE IS STILL GOING LOUDLY, (REVVING) AND THE TIRES ARE SPINNING. I WAS PUSHING ON THE BRAKE PEDAL SO HARD TO TRY AND GET THE CAR TO STOP, OR SHUT DOWN, THAT I BROKE 2 BONES IN MY FOOT. THE AIRBAGS WENT OFF, INJURING MY CHEST. I FINALLY GOT THE CAR TO STOP, BY THROWING IT IN PARK.