AP reported that Federal investigators will soon release their final report on the 2010 explosion that killed 29 men at West Virginia's Upper Big Branch coal mine.

The Mine Safety and Health Administration said that it will brief the victims' families and the media December 6 in Beaver.

The mine was run by Massey Energy but is now owned by Virginia-based Alpha Natural Resources.

MSHA, the United Mine Workers and an independent panel all agree what caused the blast.

They said that poorly maintained machines cutting into sandstone created a spark. That ignited both a small amount of naturally occurring methane gas and a massive accumulation of explosive coal dust.

(Sourced from www.therepublic.com)