Two years ago in April, 29 men were killed in an explosion at Upper Big Branch (UBB) mine in the worst U.S. coal mining disaster in four decades, devastating dozens of southern West Virginia families.

At the time of the explosion, UBB was owned by Massey Energy. Alpha Natural Resources bought Massey Energy and took over its operations last summer. The announcement to seal the mine portals, was made this year at the beginning of April. Ted Pile, Alpha’s vice president of corporate communications, said the decision to seal the mine was “clearly a consensus decision.”

He said crews have covered the concrete seals with fill dirt and are actively hydroseeding the area. “We expect to be finished with all activities at Upper Big Branch within the next few weeks.”