WHEN I PARKING MY CAR INTO THE PARKING PLACE, THE CAR SUDDENLY GAVE A ROAR AND RUSHED INTO SOMEONE'S BACKYARD. ALTHOUGH I PUSHED THE BRAKE PEDAL AS DEEP AS POSSIBLE, THE CAR RUSHED AROUND 10 METERS(?) AND FULLY STOPPED AFTER THE CAR HIT THE RODS OF WOOD STAIRCASE(TWO OF THE RODS OF STAIRCASE WAS BOKEN BY MY CAR). AT THAT MOMENT I JUST WANT SHIFT THE CAR FROM "D" TO "R" (BUT NOT YET), THE UNINTENDED ACCELERATION HAPPENED TO THIS CAR. TIME: IT HAPPENED BETWEEN 2:30 TO 3:00 PM ON NOV 30, 2017. PLACE: RUSHED INTO THE BACKYARDS OF 8352 KAVANAGH RD, DUNDALK MD 21222, THIS BACKYARDS LOCATED ON SANDY PLAINS ROAD. CONSEQUENCE: 1. SCRATCHS TO FRONT BUMPER. 2. FRONT BUMPER BECAME LOOSE AFTER COLLISION HAPPENED TO THE ROD OF STAIRCASE. 3. I HAVE STIFF MUSCLES ON BOTH THIGHS FOR TWO DAYS AFTER THIS ACCIDENT.