WE WERE APPROACHING A STOP SIGN AT AN INTERSECTION DOING ABOUT 15 MPH WHEN ANOTHER VEHICLE WHO WAS DRIVING 60MPH TRIED TO MAKE THE TURN AND HIT US PASSENGER SIDE FRONT TO PASSENGER SIDE FRONT. THIS CAUSED EXTENSIVE FRONT END DAMAGE AND FRONT RIGHT QUARTER PANEL DAMAGE TO OUR 1999 GMC SIERRA AND TO THE OTHER VEHICLE. NEITHER AIR BAG DEPLOYED IN THE SIERRA PICKUP. BECAUSE OF THE FRONT END DAMAGE THE FRAME WAS TOO TWISTED AND TOO CRIMPLED TO BE FIXED. THE BODY SHOP HAD TO REPLACE THE FRAME. THE FRAME UNDER THIS 1999 GMC PICKUP IS NO LONGER MADE AND WAS ONLY MADE AND USED THAT ONE YEAR. WHY? THE FRAME CURRENTLY BEING PLACE BACK UNDER OUR PICKUP IS MUCH MORE STURDY AND DURABLE AND IT IS A 2000 FRAME WHICH HAD TO BE ORDERED OFF THE ASSEMBLY LINE IN MICHIGAN. THE BODY SHOP EVEN HAD TO ORDER MORE PARTS TO MAKE THE FRAME WORK BECAUSE IT IS MUCH MORE HEAVY DUTY AND THE PARTS ON THE 1999 WOULD NOT MOUNT TO THE 2000 FRAME. I DID CONTACT THE MANAFACTURE GM AND I RECIEVED WORD FROM THEM LAST WEEK THAT THEY THOUGHT THE AIRBAG WERE WORKING PROPERLY EVEN THOUGH THERE WAS EXTENSIVE DAMAGE TO THE VEHICLE WHICH CAUSED THE FRAME TO HAVE TO BE REPLACED. I AM NOT SATISFIED WITH THAT AND I HAVE TOLD THEM SO. INJURES FROM THE ACCIDENT FOR THE PASSENGER INCLUDED HEAD, CHEST, BACK, BOTH KNEES WITH THE RIGHT KNEE CONTUSION MUCH WORSE (WAITING FOR MRI RESULTS) , RIGHT SHOULDER SPRANG AND BOTH FEET SPRANG. I HAVE BEEN SEARCHING THIS WEB SITE TO FIND OUT WHEN AND HOW THESE AIRBAGS SHOULD ACTIVE