FALL OF ROOF OR BACK at Armstrong Coal Company, Inc.
A roof fall occurred on the #1 unit (1st West Panel) in the #9 entry in the intersection of spad number 17+50 and extending outby through 2/3rds of the intersection of spad number 17+00 measuring approximately 70ft. long x 19ft. wide x 6ft. high. This area was supported with 4ft. fully grouted roof bolts and 8ft. cable bolts.
U.S. Mine Safety and Health Administration