A memorial in Whitesville at the entrance of the Upper Big Branch mine was erected in remembrance of 29 miners killed in an explosion. The April 5, 2010, mine explosion is the second biggest in United States history and is attributed to the failure of Massey Energy to meet basic safety standards. In addition to unsafe conditions in the mines, coal-burning power plants are killing tens of thousands of Americans, poisoning air and water, and making people sick.