WHILE FOLLOWING ANOTHER VEHICLE THROUGH AN INTERSECTION, THE FRONT VEHICLE CHANGED LANES VERY FAST AND LEFT ME IMMEDIETELY BEHIND A VECHILE STOPPED DELIVERING MAIL. I HIT MY BRAKES BUT NOT BEFORE THE VEHICE BEHIND ME SLAMMED INTO MY BACK END. I, IN TURN, HIT THE MAIL VEHICLE IN FRONT OF ME. MY VEHICLE WAS TOTALED BUT NEITHER AIR BAG DEPLOYED. THE IMPACT WAS SERVERE ENOUGH THAT THE CASING COVERING THE PASSENGER SIDE AIRBAG WAS DISLODGED BUT STILL NEVER DEPLOYED. *LA