On April 5 , 2010 , an explosion at Massey owned Performance Coal Co. mine in Montcoal , West Virginia resulted in the deaths of 29 miners . The explosion , which has become known as the Upper Big Branch Mine disaster , is the worst mining disaster in 40 years , with a greater loss of life than in any mining accident since the 1970s . The federal Mine Safety and Health Administration ( MSHA ) released its final report on December 6 , 2011 , concluding that flagrant safety violations contributed to a coal dust explosion . It issued 369 citations at that time , assessing $ 10.8 million in penalties . Investigators also noted the historical record of safety violations at the Upper Big Branch mine , which amassed more than 1,100 violations in the past three years , many of them serious , including 50 of them in March 2010 for violations including improper ventilation of methane and poor escape routes . Federal regulators had ordered portions of the mine closed 60 times over the year preceding the explosion . It was claimed , that the FBI had launched a probe investigating the possible bribery of federal officials overseeing mining industry regulation by Massey Energy
Upper Big Branch Mine disaster
Upper Big Branch Mine disaster
Massey Energy