WE WERE IN A PARKING LOT OF "KIDQUEST MUSEUM" IN BELLEVUE , WA. , TAKING OUR GRAND DAUGHTER, ONE YEAR OLD, TO THE MUSEUM. OUR CAR WAS IN STATIONARY POSITION. WE WERE TRYING TO FIGURE OUT WHERE TO PARK. DURING THIS TIME, OUR MODEL X, TOOK OFF WITH UNINTENDED ACCELERATION AND WE COULD NOT CONTROL THE CAR. IT WAS INSTANTANEOUS, OUR CAR WENT AND HIT A PARKED CHEVY VAN. THIS VAN FWENT UPSIDE DOWN AND WENT OVER THE FENCE INTO THE LOT NEXT TO IT. AFTER THE IMPACT OUR CAR WENT AND HIT ELETRIC POLE, WENT INTO BUSHES AND OVER AN ELECTRICAL BOX OF 5 BY 5. I COULD NOT OPEN THE DOOR. THERE WAS SMOKE IN THE CAR (MY WIFE THINKS SMOKE MIGHT HAVE STARTED WHILE THE CAR WAS ACCELERATING"). MUSEUM STAFF CAME AND OPENED THE PASSENGER DOOR. AFTER SHE GOT OUT, FIRST THING THEY DID WAS TO OPEN THE REAR PASSENGER DOOR AND TOOK OUT OUR GRANDDAUGHTER. I CAME OUT THRU PASSENGER DOO. FORTUNATELY NO ONE WAS HURT. MANY OF THE AIRBAGS CAME OUT. WE ARE UNBELIEVABLY LUCKY. THE PARKING LOT IS APPROXIMATELY 100 FT X 100. THIS IS THE PARKING LOT USUALLY WHERE MANY KIDS ARE IN THE LOT. FORTUNATELY THAT MOMENT THERE WAS NONE. ACCIDENT HAPPENED AROUND 4:20 P.M . WEATHER WAS GRAY BUT NO RAIN. WE STILL CAN NOT COMPREHEND HOW CAR CAN TAKE OFF AT THAT SPEED. NONE OF THE EMERGENCY BRAKING SYSTEM OR THE CAMERAS WORKED TO STOP THE CAR