The MSHA determined the miners were killed when roof-supporting pillars collapsed in an outburst that violently ejected coal over a half-mile area in the underground tunnels. Ten days later, two mine employees and an MSHA inspector died in another coal burst during rescue efforts.

Joseph A. Main, assistant secretary of labor for MSHA, said the closure of a painful chapter in modern Utah mining history will have positive reverberations throughout the U.S. coal industry. “With this settlement, Agapito takes responsibility for its role at Crandall Canyon,” Main said in a statement. “Since this tragedy, the agency has made a number of enforcement, administrative and regulatory reforms to improve the health and safety of the nation’s miners — particularly in the area of roof-control safety.”

The MHSA similarly ruled that Agapito’s analysis resulted in an inadequate design, with unsafe pillar dimensions, which contributed to the accident. Genwal and its parent company, Utah American Energy Inc., submitted their mining plan to MSHA based on Agapito’s analysis.

If approved by an administrative law judge, the settlement will mark the end of all federal government proceedings against the company tied to this incident. In Q3 2012, Genwal Resources and Andalex Resources Inc., also owned by Utah American Energy, agreed to $950,000 in civil penalties for their own violations. Genwal Resources pleaded guilty in federal court on two criminal misdemeanor counts for willful violation of health and safety standards and paid a $500,000 fine.