A ROOF FALL WAS DISCOVERED DURING A PRE-SHIFT EXAMINATION OFF THE MMU 001-0 A SOUTH PANEL. THE FALL WAS IN THE NO.3 HEADING (S.S.2574) ABOUT 200' OUTBY THE FACE. THE FALL MEASURED APPROX. 70'L X 20'W X 8-10'H. THERE WERE NO INJURIES OR EQUIPMENT DAMAGED.