VEHICLE WAS INVOLVED IN A HEAD-ON COLLISION WITH ANOTHER SUV ("T-BONE"). SPEED WAS APPROXIMATELY 35-45 MPH HIT BRAKES, BUT OTHER VEHICLE PULLED IMMEDIATELY OUT IN FRONT OF VEHICLE IN QUESTION. SMASHED FRONT END OF VEHICLE EQUALLY ON BOTH SIDES (SQUARE IMPACT) AND CAUSED CONTENTS FROM VEHICLE TO COME FROM FAR BACK TO THE FRONT SEATS. WENT FROM 45-0 MPH IN A FEW FEET (ALMOST FLIPPED OTHER SUV), YET AIR BAGS DID NOT DEPLOY. FORCE CAUSED SEATBELT TO COMPLETELY STRETCH OUT AND LOCK IN PLACE PERMANENTLY. (WOULD NOT RETRACT AFTERWARDS) ALL WITNESSES INCLUDING POLICE, TOW TRUCK, AND INSURANCE COMPANY SAY AIRBAGS SHOULD HAVE DEPLOYED. THE CAR IS SCHEDULED FOR REPAIRS AND WE ARE TERRIFIED TO GET IT BACK IN REPAIRED CONDITION. WE DO NOT WISH TO ENDANGER THE LIVES OF OUR FAMILY AND GM IS NOT REPLYING. DT