THE VEHICLE WAS STATIONARY, PARKED ON LEVEL AND DRY ASPHALT, WAS STARTED AND LEFT RUNNING IN NEUTRAL FOR ABOUT 30 SECONDS. WHILE PARKED AND UNATTENDED, THE VEHICLE MADE A STRANGE SOUND, POSSIBLY INDICATING THE VEHICLE SHIFTED INTO A FORWARD-MOVING GEAR, OR THE KICK STAND FAILED, AND THE VEHICLE THEN FELL OVER, COLLIDING WITH THE GROUND ON LEFT SIDE OF THE VEHICLE.