WHILE WAITING AT STOP LIGHT ANOTHER VEHICLE REARENDED VEHICLE. UPON IMPACT, FRONT SEATBACKS COLLAPSED BACKWARDS INTO THE REAR. THEN, VEHICLE WAS PUSHED INTO A DITCH , AND AIR BAGS FAILED TO DEPLOY. PASSENGER SUFFERED BROKEN BACK AND LEG. DRIVER SUFFERED SEVERE BACK SPRAIN. VEHICLE WAS TOTALED.*AK *YD