EXITING THE 215 NORTHBOUND, WE STOPPED AND PARKED AT A STORE. WHILE PARKED THE INDICATOR LIGHT CAME ON FOR LOW TIRE PRESSURE. I DID NOT PAY THAT MUCH ATTENTION BECAUSE THE CAR INDICATOR LIGHT HAS COME ON BEFORE AND THE CAR HAD RECENTLY HAD ITS ROUTINE MAINTENANCE CHECK. WHEN DRIVING WAS RESUMED THE CAR BEGAN TO WOBBLE. ASSUMING WE HAD A FLAT, WE ATTEMPTED TO DRIVE TO A MORE ILLUMINATED AREA TO INSPECT THE CAR AND CALL ROAD SIDE SERVICES. THE CAR AT THIS POINT WAS BEGINNING TO DECELERATE ALMOST TO A STOP SO I INCHED CAR ONTO AN UNPAVED AREA. I ASSUMED THE CAR'S SLOWING AND STOPPING ON ITS OWN WAS A SAFETY FEATURE. AS I PULLED TO THE SIDE OF AN UNPAVED CITY ROAD, I HAD MY FOOT ON THE BRAKE BUT NOT IN THE PARKING GEAR. THE CAR WAS STATIONARY AS MY SISTER EXITED THE CAR AND TO INSPECT THE TIRES. THE RIGHT REAR PASSENGER TIRE WAS FULLY DEFLATED. MY TWO DAUGHTERS WERE ABOUT TO GET OUT OF THE CAR SO HAD UNFASTENED THEIR SEATBELTS. THIS IS WHEN THE CAR MADE A QUICK SUDDEN JERK FORWARD, I PRESSED MY FOOT ON BRAKE TO MAKE SURE THE CAR WAS AT A COMPLETE STOP AND THAT WAS WHEN IT FELT LIKE A FORCE HAD PUSHED THE CAR TO TOP SPEED, AN SUDDEN UNINTENDED AND FORCEFUL ACCELERATION. I ATTEMPTED TO BRAKE BUT I HAD NO CONTROL. I WAS TRYING TO AVOID HITTING THE POLE, BUT ALSO HAD NO CONTROL OVER THE STEERING WHEEL. THE CAR COLLIDED WITH A WATER VALVE/POLE AND CHAIN LINK FENCE AT TOP SPEED.