FALL OF ROOF OR BACK at Pinnacle Mining Company LLC
Roof fall at West Mains track, #5 Entry at #146 break. Rock measured 20' X 20' X 9'. The location was mined in JUL 1989 and was bolted with 4' fully grouted bolts and 6' cable bolts. The fall occurred 36,260' from the face.
U.S. Mine Safety and Health Administration