THE EMPLOYEE WAS PERFORMING MAINTENANCE ON THE AIR CONDITIONING UNIT OF A DOZER. HE PLACED HIS HAND NEAR THE AIR DUCT TO CHECK FOR AIR FLOW ANDTEMPERATURE. THE GUARD HAD BEEN REMOVED AND A VANE FROM THE SQUIRREL CAGE APPARENTLY EXITED THROUGH THE DUCT AND STRUCK THE EMPLOYEE'S LEFT MIDDLE FINGER. SUTURES WERE REQUIRED.