EMPLOYEE STATED, WHILE INSTALLING THE THIRD ROW OF BOLTS IN A TURNED RIGHT BREAK, A PIECE OF CAP COAL LAYERED WITH ROCK MEASURING 3'LONG BY 2'WIDE BY 4'THICK FELL FROM THE ROOF AND RIB STRIKIN G HIS LEFT ANKLE. HE HAD ALREADY INSTALLED OUTSIDE BOLT AND WAS SWINGING HEAD IN TO INSTALL INSIDE BOLT. EMPLOYEE CONTINUED TO WORK HIS REGULAR SHIFTS. HE SAW SPECIALIST 1-22-04. OFF 1-28-04.