LOST CONTROL OF CAR. FIRST IMPACT WAS A TREE STUMP AS CAR WAS TURNING, HIT TREE STUMP. SHE WENT FORWARD AND HIT HEAD ON STIRRING WHEEL. AIR BAG AT STEERING WHEEL DID NOT INFLATE OR DEPLOY. ONLY SIDE DOOR ON LEFT SIDE FILLED WITH AIR.SECOND IMPACT CAR TILTS OVER THEN AIRBAG ON SIDE DOOR INFLATE. THE CAR WAS IN MOTION, ON A RESIDENTIAL STREET.