AIR BAG DRIVER TYPE UNKNOWN-- DRIVER STERNUM FRACTURED I WAS DRIVING A 2001 MERCEDES CLK320 DURING RUSH HOUR TRAFFIC 1/2 CAR LENGTH BEHIND NEXT CAR. THE CAR IN FRONT OF ME CHANGED LANES, TWO 3 SERIES BMWS WERE STOPPED FOR CITY BUS. I SLAMMED ON BRAKES, THEN REALIZED I WOULD HIT THE CAR IN FRONT, DID NOT SWRIVE LINED MY BODY UP BOTH ARMS ON WHEEL SKIDDED AND HIT THE CAR IN FRONT OF ME. THE AIRBAG HIT ME IN THE CHEST VERY HARD AT ABOUT 1300, THERE WAS A TEAR WITH WHITE PUFF AND LITTLE METAL BEAD THINGS ON AIRBAG. I CHECK TO SEE IF MY FILINGS HAD BEEN BROKEN. I HAD NO IDEA WHAT THE LITTLE METAL CIRCLE WAS. I COULD MOVE MY HANDS, FEET WITHOUT NUMBNESS OR TINGLING NECK DIDN'T HURT, CHEST HAD SHARP PINPOINT PAIN, THERE WAS SMOKE, ENGINE WAS DAMAGED I WAS WORRIED ABOUT FIRE. REACHED FOR SEATBELT A GUY WANTED ME TO STAY. THEN FIREFIGHTER SAID TO LEAVE TO SPRAY. EMS ON SCENE. TRANSPORTED TO NFRMC CT CHEST STERNAL FRACTURE NOT DISPLACED. POLICE REPORT IS WRONG. AIRBAG DEPLOYED, EMS TRANSPORTATION. RECORDS AVAILABLE CLK TOTALED, ENGINE DAMAGE SPEED EST 25 M/HR FLOW OF TRAFFIC LIMIT 45.