Unitentional roof fall occured in #4 entry outby the tailpiece of 004 section.The fall occured 20' inby spad station #7701.The fall measured appx. 20' W x6' to 8' H x 120 L.area was supported by 4' fully grouted bolts.#3 Stamler MBC was caught by this fall, ventilation was not interrupted & roof fall will be cleaned up.