Alpha Seals West Virginia Mine Where 2010 Blast Killed 29

Alpha Natural Resources has completed sealing the West Virginia mine where an explosion killed 29 workers in 2010.

Alpha spokesman Ted Pile told The Register-Herald that crews put the final concrete seal in place at the Upper Big Branch mine on Wednesday. The seals are covered with fill dirt.

The mine hasn’t operated since the explosion on April 5, 2010. It was the worse U.S. mine disaster in four decades.

Virginia-based Alpha acquired the mine in Montcoal last summer when it bought Massey Energy. Alpha announced earlier this year that it would seal the mine’s portals, which are large tunnels used by miners to get underground.

Pile says Alpha will complete all activities at the mine within the next few weeks.