The fall occurred in the #1 return entry of Southwest Mains 70 ft inby survey station 970. The fall was in an intersection and measured 20 ft wide by 20 ft long by 8 ft thick. The fall did not impair ventilation and we do not intend to clean up the fall. It was blocked off by setting 8 breaker timbers in all entrances. No persons or equipment involved. Roof fall only.