EE WAS INSTALLING BOLTS IN THE #4 ENTRY LEFT CROSSCUT, EE WAS OPERATING OPERATOR SIDE OF ROOF BOLTER WHEN A PIECE OF ROCK FELL FROM TOP STRIKING CANOPY, BOUNCING OFF CANOPY STRIKING HIM ON HIS LEFT ANKLE. EE COMPLETED WORK SHIFT. WENT TO DR ON 1-10-03. X-RAYS OF HIS ANKLE REVEALED FRACTURE TO HIS ANKLE (LEFT).