I HIT A SMALL DEER DOING ABOUT 35 MILES PER HOUR AND PULLED OVER TO THE SIDE OF THE ROAD ABOUT THREE MINUTES LATER ANOTHER AUTO CAME UP FROM BEHIND AND REAR ENDED ME MY AIR BAG DEPLOYED THEN. WHY DID IT DEPLOY THEN AND NOT WHEN I HIT THE DEER. THE ONLY DAMAGE I DID TO THE FRONT END TO MY TRUCK WAS CRACKED THE GILL AND OTHERS AROUND IT. THE DAMAGE THAT THE OTHER AUTO DID WAS BENT THE BUMPER UNDER MY TRUCK ALONG WITH THE BRACKETS TOO, THE IMPACT FROM THE OTHER AUTO WAS LOUD AND WAS HEARD FROM ABOUT A MILE AWAY. THE AUTO THAT REAR ENDED ME WAS GOING ABOUT 55 TO 60 MILES PER HOUR. *JB