I WAS BACKING OUT OF A PARKING SPACE IN A PARKING LOT. I PUT THE CAR IN REVERSE, PLACE MY FOOT ON THE BRAKE, PUT THE CAR INTO DRIVE, LIFTED MY FOOT OFF OF THE BRAKE AND THE CAR IMMEDIATELY BEGAN TO ACCELERATE WITHOUT MY FOOT EVEN TOUCHING THE ACCELERATOR. WHEN I PUT MY FOOT ON THE BRAKE, THE BRAKE PEDAL WENT ALL THE WAY DOWN TO THE FLOOR WITHOUT STOPPING THE VEHICLE. THE VAN STRUCK ANOTHER VEHICLE THAT WAS PARKED IN THE PARKING LOT, WENT OVER THE CURB OF THE PARKING LOT, DOWN AN EMBANKMENT INTO A RAVINE AND HEADED TOWARDS A TREE. THE PASSENGER THAT WAS IN THE FRONT SEAT THEN REACHED OVER AND PUT THE CAR INTO PARK, WHICH BROUGHT THE CAR TO A STOP. THE WHOLE TIME THE CAR WAS MOVING I WAS TRYING TO STOP THE CAR BY PUMPING THE BRAKES, BUT THEY DID NOT WORK. THE CAR WAS ACCELERATING THE ENTIRE TIME UNTIL THE PASSENGER STOPPED IT BY SHIFTING INTO PARK. THE AIRBAGS DID NOT DEPLOY. DAMAGE WAS DONE TO THE FRONT PASSENGER BUMPER AND SIDE OF THE CAR, THE DRIVER'S SIDE FRONT TIRE EXPLODED. AFTER THE ACCIDENT, THE BRAKES DID FUNCTION.