WHILE APPROACHING INTERSECTION A VEHICLE TRAVELING PERPENDICULAR TO US FAILED TO STOP AT STOP SIGN. THIS VEHICLE ENTERED THE INTERSECTION AND WE "T-BONED" THE VEHICLE. OUR VEHICLE SUSTAINED A DIRECT HIT ON THE FRONT OF THE VEHICLE AND THE AIR BAGS NEVER DEPLOYED. AFTER THE INITIAL COLLISION OUR VEHICLE REMAINED IN CONTACT WITH THE VEHICLE THAT FAILED TO STOP AND BOTH OF OUR VEHICLES WERE DRIVEN DIRECTLY INTO A TREE, THUS INCURRING ANOTHER SIGNIFICANT IMPACT ( MORE SIGNIFICANT THAN THE INITIAL COLLISION W/ THE OTHER CAR ) AND THE AIR BAGS STILL DID NOT DEPLOY. THERE WERE 2 PEOPLE IN THE FRONT SEATS AND 2 PEOPLE IN REAR SEATS. ALL SUSTAINED INJURIES AND NEEDED OR STILL REQUIRE MEDICAL ATTENTION. THE TWO PASSENGERS ON THE OTHER VEHICLE WERE FATALLY INJURED. THERE HAD NEVER BEEN ANY INDICATION OF AIR BAG FAILURE AND NEVER ANY WARNING "IDIOT" LIGHTS ON THE DASHBOARD EVER AT ANY TIME INDICATION ANY ISSUES W/ AIR BAG FUNCTIONALITY. WITH RECENT EVENTS SHOWING FAILURE OF GM AIR BAGS, I BELIEVE THIS IS ANOTHER INDICATION OF THIS FAILURE WHICH NEEDS TO BE INVESTIGATED. SAFETY FEATURES ARE SOMETIMES TAKEN FOR GRANTED IN VEHICLES, BUT WHEN NEEDED TO PERFORM, THEY ARE EXPECTED TO PERFORM AS ENGINEERED. THESE SAFETY FEATURES ARE FACTORED INTO THE DECISION MAKING OF VEHICLE PURCHASES AND ARE EXPECTED TO PERFORM. *TR