WHILE CLEANING OFF OF THE TOP OF A CONTINUOUS MINER, A ROCK WEIGHING 20 LBS. FELL ABOUT 2', STRIKING THE OPERATOR ON THE TIP OF HIS LT. MIDDLE FINGER. EVEN THOUGH THE OPERATOR WAS WEARING GLO VES, THE ROCK SMASHED THE TIP OF THE FINGER BEHIND THE NAIL, EXPOSING THE BACK OF THE NAIL & BREAKING THE BONE BENEATH THE NAIL BED. TREATMENT INCLUDED SUTURING.