The agency said that the company had “implemented changes to the roof control plan” and that the DEP Bureau of Mine Safety concluded inspections prior to the announcement.

Eric Benjamin Hill, 30, a continuous miner operator, died from asphyxiation when he was crushed by a roof fall. After the accident, the second in Pennsylvania mines in 2005, the DEP ordered the mine idle. The US Mine Safety and Health Administration granted the mine’s new roof-control plan on January 27.

The agency said Rosebud had agreed not to mine in the accident area until a detailed geologic examination had been completed that could determine if additional precautions needed to be taken.

“Our Bureau of Mine Safety conducted a thorough investigation into the fatal roof collapse in the mine and ordered Rosebud to take the necessary actions to ensure that it is safe for miners to return to work,” DEP deputy secretary for mineral resources management J Scott Roberts said.

“Underground mine inspectors will monitor implementation of the new roof plan, and the department will continue to pursue legal action against the certified mine officials involved in this fatality.”

While the investigation was underway, the agency cited the mine foreman Michael Roudybush, general assistant mine foreman Michael Kunselman, section foreman James Waltenbaugh and roof bolter John Kaplon for improperly installed roof bolts at the accident scene that may have been a factor in the collapse; and suspended all of the workers’ state certifications. Additionally, it formally filed to have the mine officials’ certifications revoked.

Rosebud is the third largest underground coal producer in Pennsylvania and operates nine deep mine complexes in five counties of the western area of the state.

The accident was not the only one at a Rosebud mine last year: Boyd Alfred Beer Jr, 26, died at the company's Tracy Lynne room and pillar facility in June, also due to a roof fall.