AN UNINTENTIONAL ROOF FALL WAS DISCOVERED ON 8/7/01 IN THE #2 ENTRY (NEUTRAL) AT BREAK 123. FALL WAS APPROXIMATELY 6'HIGH X 18'WIDE X 20'LONG (INTERSECTION). NO INJURIES, NO EQUIPMENT CAUGHT, VENTILATION WAS NOT INTERRUPTED. THE AREA HAD BEEN BOLTED WITH 6' REBAR TENSION BOLTS.