(CHARLESTON, W.Va.) — The state of West Virginia Thursday released what is expected to be the final report on the investigation into the Upper Big Branch mine explosion that killed 29 people in April 2010.
The report, like three others, says a methane explosion at the mine was exacerbated by coal dust. Massey Energy — owner of the Upper Big Branch mine — favored production over safety and failed to properly rock dust the mine, according to the report.
The state issued 253 citations against the coal company. Those violations were for improper ventilation, equipment problems, and personnel issues pertaining to the foreman or fireboss, among other areas.
The explosion at Upper Big Branch has been called the worst U.S. mining disaster in nearly 40 years.
Copyright 2012 ABC News Radio
Ashley Fantz and AnneClaire Stapleton, CNN Newswire
Tom LoBianco, CNN