It's not looking good for the four coal miners still missing in Montcoal, West Virginia, where the worst U.S. mining accident in over two decades is still developing. Rescuers drilled their first hole into the mine and banged on the drill pipe for 15 minutes on Wednesday to signal to possible survivors. Unfortunately, no one banged back. An explosion at the mine killed 25 people on Monday, and the ensuing buildup of methane gas and carbon monoxide complicated rescue efforts, as crews had to dig holes in order to ventilate the area. Once the mine is ventilated, rescuers will journey four or five hours underground to reach the area where the remaining miners could be trapped. Massey Energy Co. runs the mine and received numerous violations for it, including recent violations for ventilation problems.