The deaths of 29 coal miners at the Upper Big Branch coal mine in West Virginia owned by Massey Energy were "entirely preventable" according to a report issued by the Mine Safety and Health Administration.  The exhaustive report concluded as follows:

Massey routinely ignored obvious safety hazards and let conditions develop that allowed a small methane ignition to propagate into a massive coal dust explosion," the MSHA report said. "The tragic deaths of 29 miners and serious injuries to two others at Upper Big Branch were entirely preventable. 

Read the report of the Mine Safety and Health Administration.