A ROOF FALL IN THE EAST MAINS AT CROSSCUT #9 IN THE INTERSECTION OF #1 ENTRY CONTINUING THROUGH THE INTERSECTION OF #2 ENTRY MEASURING 73' X 19' X 6'. THE AREA WAS MINED IN APRIL 2000 AND SUPPORTED WITH 6' TENSION REBAR BOLTS AND 6"" X 6""SQUARE TIMBERS. THE FALL WAS CAUSED BY AN UNDETECTED SLIP.