An unplanned roof fall was discovered at 9:45 a.m. on a routine airway exam in the #1 entry of the return entry at Spad Station # 1695. This is app.5,300 ft. from any section. Size of fall is 90ft. in length X 19 ft. in width X 6-8ft high. It was bolted with 6' tourque tension bolts. This will not be rehabilitated but the brattice line will be re-routed.