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U.S. Department of Labor

Mine Safety and Health Administration
201 12th Street South, Suite 401
Arlington, VA 22202-5450

Dear Underground Mine Operators, Miners and Miners' Representatives

I want take this opportunity to alert you about the hazards related to underground coal mine rib rolls. In 2010, the number of fatal coal mine rib falls exceeded fatal roof falls for the first time ever. Very recently, within two days, separate rib roll/fall accidents claimed the lives of two coal miners in West Virginia and Kentucky.

While the number of roof fall fatalities has gone down by about 62% since the 1990's (from an average of 9.6 per year in the 1990's to 3.6 per year during the last five years), the incidence of rib fall fatalities has remained approximately constant (about 1.5 per year). In addition, injuries associated with pillar rib failure have been steady at approximately 100 per year. The persistence of rib fall injuries, underlined by the recent increase in rib fall fatalities, has led to this investigation of the coal rib failure parameters and methods available to mitigate rib failure in U.S. underground coal mines.

I want to remind everyone that increased vigilance is an absolute must. The potential for rib fall hazards is always present. The injury rates increase substantially as mining height increases. Mine operators, miners, and miners' representatives should review the mine roof control plans regularly to remain familiar with all plan requirements, especially where they apply to rib support and protection. Review examination procedures, training plans (including new miner, newly employed experienced miners, retraining and task training), to assure adequate procedures, controls and examinations are in place and that all miners are well trained to prevent these fatalities.

On April 21, 2011, MSHA issued a Program Information Bulletin (PIB) which discussed conditions that contribute to rib fall hazards and the suggested methods for protecting miners from these rib falls. This bulletin can be found on MSHA's website here:

In addition, as part of the agency's 2011 Preventive Roof/Rib Outreach Program (PROP), MSHA inspectors will distribute important informational materials about rib rolls at underground mining operations which include, "Coal Mine Rib Control for Mine Operators," a brochure which provides safety advice and tips for mine operators to consider in maintaining proper roof and rib control. For additional information, please visit MSHA's website at and review the single source page concerning rib failure accidents.

Joseph A. Main
Joseph A. Main
Assistant Secretary for
Mine Safety and Health