Alpha Natural Resources marked the two-year anniversary of the worst mining accident in the U.S. in four decades by announcing that it would permanently seal the portals to the Upper Big Branch (UBB) Mine where 29 miners where killed in a explosion on April 5, 2010.

Alpha Natural Resources acquired the mine when it acquired Massey Energy Corp. in June of 2010, following the deadly blast.

On April 5, 2012 Alpha Natural Resources made the announcement that the portals that allow entry to the mine will be permanently sealed with concrete barriers that prevent future access, and areas around the portals will be reclaimed. All boreholes will be plugged and mine fan shafts will be capped, barring access to the mine. The work is expected to commence shortly and be completed this summer.

“Though two years have passed, everyone still has vivid memories of the tragedy and the suffering the miners’ families endured. For all of us in the mining industry, it is a solemn reminder of why we must always put safety first in everything we do at work and at home. Our hearts go out to the families of those lost at UBB on this anniversary of the accident,” said Kevin Crutchfield, Alpha Natural Resources’ chief executive officer.

“When Massey joined Alpha last year, we brought all 7,000 Massey employees through our proprietary Running Right safety process, which led to a significant improvement in safety performance. We are currently making significant safety-related investments in leading-edge technologies that will make coal mines safer throughout the industry. And this June, Alpha will break ground on the Running Right Leadership Academy, a state-of-the-art center for safety training that eventually will be open to the entire industry. While we wish this tragedy had never happened, we are committed to doing our part in helping the coal industry continuously improve its safety performance,” said Crutchfield.

Alpha is working on the plan to seal UBB with the U.S. Mine Safety and Health Administration, a unit of the federal Department of Labor, and the West Virginia Office of Miners’ Health Safety and Training.