MY 2011 GMC TERRAIN HIT A VEHICLE IN FRONT, CAUSING MAJOR DAMAGE (THE VEHICLE IS TOTALED OUT) AND NO AIR BAGS DEPLOYED. MY VEHICLE WAS TRAVELING AT APPROXIMATELY 55 MPH NORTHBOUND IN THE #3 LANE OF THE 41 FREEWAY, SOUTH OF THE SHAW EXIT. IMPACT WAS ESTIMATED TO BE BETWEEN 20 TO 30 MPH. THE DRIVER, MY 18 YEAR GRAND-DAUGHTER HIT HER HEAD ON THE STEERING WHEEL AND HER LEFT WRIST WAS INJURED HOLDING ON TO THE STEERING WHEEL. THE 18 YEAR OLD FEMALE RIGHT FRONT SEAT PASSENGER SUFFERED AN ANKLE INJURY. WHY DID THE AIR BAGS FAIL TO DEPLOY, WITH A STRAIGHT ON FRONT END COLLISION WITH THE VEHICLE IN FRONT?! UNACCEPTABLE!!!