AN UNINTENTIONAL ROOF FALL OCCURRED ON THE 1 WEST BELT AT 8 XCUT. (AWEST, #3 ENTRY AT 5+50 FT.). THE FALL OCCURRED IN THE OLD 1SOUTH BELT TRENCH. THE FALL WAS 30' LONG, 12' WIDE, AND 4' HIGH. FOUR FEET CONVETIONAL BOLTS & SCREEN WERE USED IN THE ROOF OF THE OLD BELT TRENCH. CRIBS WERE SET ALONG RIBLINE OF THE BELT. SOME 8' POINT ANCHOR BOLTS WERE ALSO USED. DETERIORATION OF THE IMM