FALL OF ROOF OR BACK at Rockwell Mining LLC
Retreat mining on the #1 Section. The CM broke down in the #2 Entry for approx. 2.5 Hrs. The pillar line began to work. Once the CM was repaired, the #2 jack was moved up approximately 5' and reset. As the pressure was relieved from the #1 jack, the gob area began to fall in the #1 Entry and rode over into the #2 Entry onto the jacks. The fall was approx. 19'W x 28'L x 6'H.
U.S. Mine Safety and Health Administration