The nation's biggest coal company, Peabody Energy (BTU), filed for Chapter 11 bankruptcy protection on Wednesday as the coal industry grapples with the fallout of low natural gas prices, costly regulations and legacy costs.
Peabody had warned in March that "sustained depressed" coal prices had placed it on the edge of insolvency.
The company also suffered a sharp blow from its exposure to the bankruptcy of former subsidiary Patriot Coal, one of several coal giants to topple into bankruptcy court over the last couple years.