SEVERAL WORKERS WERE REPLACING BLOW BARS IN A ROCK CRUSHER. THE OPERATION WAS COMPLETELY SHUT DOWN WHILE REPLACEMENT WAS BEING MADE. THE WORKERSHAD PERFORMED THE TASK SEVERAL TIMES & WERE HAVI NG NO PROBLEMS. THE PARTS INVOLVED ARE QUITE HEAVY & AKWARD. WHILE MANUEVERING THE PART, ONE OF THEM SIMPLY ROLLED ONTO INJURED'S FINGER, CRUSHING THE TIP.