WHILE OPERATING THE ROOF BOLTER, A ROCK FELL STIRKING HIS CANOPY AND CAUSING HIM TO TURN AND MOVE SUDDENLY. HE STATED HIS KNEE THAT HE HAS HAD SURGERY ON BEGAN TO HURT. HE WENT TO HIS PHYSICIA N ON 6-26-01 AND WAS TOLD THAT NOW NEW INJURY HAD OCCURRED, BUT PROBLEMS WERE DUE TO OLD INJURY. NO INFO WILL FOLLOW WHEN WE RECEIVE THE DR. REPORT.