A roof fall occurred in the 9 North Panel #9 entry in mid pillar between cross-cut #30 and cross-cut #31 extending inby through the pillarline between cross-cut #32 and cross-cut #33. The fall measured approximately 90ft. x 19ft. x 5.5ft. The area was supported by 5ft. fully grouted roof bolts. An undetected slip was determined to be the cause of the fall.