I WAS DRIVING EAST ON F.M. 356 AT ABOUT NOON. I WAS TRAVELLING ABOUT 50 MPH. A CAR TURNED IN FRONT OF ME AND I ATTEMPTED TO PASS THE CAR. I WAS UNABLE TO DUE TO ONCOMING TRAFFIC, SO I QUICKLY RETURNED TO MY LANE. ONE OF MY TIRES WENT OFF ONTO THE UNPAVED SHOULDER AND I WENT DOWN A SMALL EMBANKMENT. IT WAS MUDDY SO I COULD NOT STOP. I HIT A LARGE PINE TREE HEAD ON AND STOPPED. BOTH OF US WERE WEARING OUR SEATBELTS. MY AIRBAG FAILED TO DEPLOY CAUSING MY HEAD AND TORSO TO STRIKE THE STEERING WHEEL. I SUFFERED 6TH NERVE PAULSEY AND AN ANUERISM DEVELOPED ON MY AORTA. THE AORTA HAD TO BE SURGICALLY REPAIRED. MY GRANDDAUGHTER'S AIRBAG HAD BEEN TURNED OFF DUE TO HER SMALL SIZE. SHE SUFFERED A BROKEN LEG AND A SLIGHT CONCUSSION. THE TRUCK WAS TOTALLED. *AK