Massey Energy Company, operator of the West Virginia mine where at least 25 were killed Monday, had been warned in 2007 by the Mine Safety and Health Administration that it faced problems, a "potential pattern of violations" as a letter put it. But issues continued—although the mine avoided stricter federal oversight after slowing its rate of violations in 2008, since last year the mine had some 50 notices of problems at the mine that it failed to correct, the New York Times reports. Massey declined comment. Meanwhile, hopes of finding survivors dimmed as rescuers were forced to leave the mine Friday morning amid pockets of smoke that could indicate a fire. Rescuers have hoped that up to four miners might have successfully navigated their way to an airtight chamber designed for such a disaster.