Foreman as walking the intake airway when a fall was dicovered @ 8:55 am. Location was break 15 #7 heading spad # 324. Fall was 65' long x 18 1/2' wide x 4' thick. Area was dangered off and cribs set at all entrance points. 5' torque tension bolts were installed previously in this area. Falling rock pulled some of the bolts from their anchorage point.