AN UNINTENTIONAL ROOF FALL OCCURRED IN THE 1ST N. SUB-MAINS, XC-20, BETWEEN #1 & #2 ENTRIES. APPROX. 20' L x 15' W DOME. THE AREA WAS BOLTED W/5' RESIN GROUTED BOLTS PRIOR TO OPERATORS CHANGE IN ROOF CONTROL PLAN TO 6' RESIN GROUTED BOLTS. THE FALL HAS NOT IMPEDED TRAVEL, AIR OR ESCAPEWAYS. NO INTERSECTION WAS INVOLVED. THE AREA HAS BEEN TIMBERED AND DANGERED OFF.