A new study is shedding light on just how hard the coal industry has been hit in recent years.

Researchers from the University of Tennessee and West Virginia University found that while the industry has been hurt across the country, East Tennessee and other parts of Appalachia have suffered even more so.

Coal production has seen a massive decline – around 45 percent around Appalachia and around 21 percent across the United States – from 2005 to 2015.

The study finds that demand for coal is declining due to what researchers call a “perfect storm” of factors – lower natural gas costs, tougher regulations that have increased the cost of coal for power plants, and weak demand for coal on the international level.

Researchers forecast that the drop in coal output will level off and even see a modest recovery in the Appalachian region, but that’s only expected to be a small fraction of the decline seen over the last decades.

More online: Read the full study