An unintentional roof fall was discovered on 9 North Mains in the Primary Escapeway (Intake), #3 and #4 Entries, from Brk #37 to Brk #38. The fall is approximately 20 ft. thick. All affected personnel were removed outby the fall, except those required to perform support work. No injuries or entrapments occurred. MSHA and WVMHST Officials were notified and are currently on-site.