An unplanned rock fall occurred in the #5 entry of the #5 left panel, 8 breaks inby the section headdrive located off the #3 Left Sub-Mains off the #3 West Sub-Mains. Miner was extracting coal on 1st run on the right wall cut when intersection fell in and rode thru the breaker timbers. Rock fall measured approximately 40'x20'x42"".