THE CIRCUMSTANCES OF THIS ACCIDENT WERE UNUSUAL. ROAD CONDITIONS WERE CLEAR AND DRY. NO APPROACHING CARS IN EITHER DIRECTION, NOTHING IN THE ROAD TO CAUSE A PROBLEM. I TURNED THE VAN LEFT FROM THE DRIVEWAY, WHICH HAS A RAISED "HUMP" AT THE END, AND BEGAN HEADING WEST ON EAST SWON. I WAS TRAVELING ABOUT 15-20 MPH, BOTH HANDS ON THE WHEEL AND LOOKING STRAIGHT AHEAD ABOUT HALF A BLOCK TO A STOP SIGN AT THE NEXT CORNER. THE VAN PULLED TO THE RIGHT. I TRIED TO TURN THE WHEEL LEFT, WITHOUT RESPONSE. THE VAN GRAZED A UTILITY POLE. I APPLIED THE BRAKE AND KEPT TRYING TO TURN. IMMEDIATELY PAST THE UTILITY POLE WAS A STORM SEWER, WHICH THE RIGHT FRONT TIRE STRUCK, VIRTUALLY SHEARING OFF THE TIREAND DETACHING THE AXLE. THE VAN STOPPED ABOUT 30 FEET FROM WHERE IT FIRST JUMPED THE CURB. AIRBAG DEPLOYED; THERE WAS A DOUBLE "BANG" SOUND DURING THE MIDDLE OF THE ACCIDENT. THE STEERING WAS UNRESPONSIVE DURING THE ENTIRE ACCIDENT. IT SEEMS THAT SOMETHING HAPPENED IN THE NATURE OF A MECHANICAL FAILURE TO CAUSE THIS ACCIDENT. SEVERAL DAYS PRIOR, THE CAR HAD BEEN SERVICED BY A REPUTABLE MECHANIC WHO SAID WE NEEDED A "MOTOR MOUNT"; OURS HAD A STRESS FRACTURE. HE INDICATED THE CAR WAS DRIVABLE, AS THE PART WAS DUE TO ARRIVE ON WEDNESDAY, DECEMBER 6. I ASKED THE MECHANIC IF HE THOUGHT WE NEEDED THIS PART DUE TO A FAULTY MOUNTING OF A NEW ENGINE DURING A RECALL REPLACEMENT OF OUR MOTOR APPROXIMATELY 2 YEARS AGO. HE SAID THAT SOME CARS WEAR MOTOR MOUNTS OUT QUICKER DUE TO DESIGN, AND THAT CORROSION CO