Coal mining company Genwal Resources has pleaded guilty to corporate criminal charges stemming from the 2007 Crandall Canyon mine collapse in Utah that left nine miners and rescuers dead.
Federal prosecutors say a plea agreement includes a provision that no criminal charges will be filed against any individuals in the case.
Federal and congressional investigators blamed the an initial mine collapse on "retreat mining," in which pillars of coal holding up the roof of the mine are dug out, causing collapse of the mine behind them.
Retreat mining was specifically forbidden by the federally-approved roof control plan for the mine. The two misdemeanor counts charged in the plea agreement include a willful violation of mandatory health and safety standards involving retreat mining four days before the initial August 7 mine collapse, which trapped and killed six miners.
But prosecutors say they were unable to demonstrate, given the evidence, a direct connection between the violation and the fatal mine collapse.
"We were unable to prove beyond a reasonable doubt that the company's actions caused the mine collapse," said David Barlow, the U.S. Attorney for Utah.
The other charge involves the failure to report an earlier mine collapse in which no one was injured.
The plea agreement calls for $500,000 in fines and must still be approved by a federal judge.
Three rescuers were killed and six others injured in another mine collapse during a rescue effort that was eventually abandoned. The bodies of the six miners initially killed remain in the mine, which has been sealed.