[img]http://d.yimg.com/a/p/ap/20100406/capt.5b90dec8aaba4f53bdbf512b0a0203f2-5b90dec8aaba4f53bdbf512b0a0203f2-0.jpg?x=130&y=86&q=85&sig=einP3NMkvadw5sleM1YdBA--[/img]AP - An explosion at a coal mine with a history of safety problems killed 25 workers and at least four others were missing early Tuesday more than a thousand feet underground in the worst U.S. mine disaster since 1984.