On September 12, 1984, coal production in the Berger No. 2 Mine was halted to permit repair of a bridge conveyor. Moments later, the creaking of posts prompted some miners to flee the face area.
Soon after, a large portion of the roof fell, covering the bridge conveyor and part of the mining machine. The collapse instantly killed four men, and seriously injured another.
MSHA investigators determined that the disaster was caused by the following conditions/practices:
Violations of the roof control plan, including excessive entry widths, missing permanent supports, the unapproved second mining of pillars, and a failure to provide a supply of supports within 500 feet of the face.
In addition, the failure to provide additional roof supports in areas having subnormal roof conditions, as evidenced by horsebacks and swags in the mine floor, also violated the roof control plan.
Faulty pillar recovery methods, including the complete extraction of pillars, and a failure to install posts during and after mining.
Failure to provide an accurate mine map at the surface.
Failure to conduct a preshift examination that would have identified subnormal roof conditions on the day of the disaster.
Historical Summary of Mine Disasters in the United States - Volume II