The report said the mine managers utilised pillar recovery methods that were incompatible with prevailing geological conditions of the 6-left panel, where the accident occurred.

The continuous mining machine operator was killed by a coal/rock burst while retreat mining approximately 15-20 feet underground.

The report also said the mine operator failed to follow the MSHA-approved roof control plan.

The approved plan allowed for altered pillar recovery methods and sequences based on changing geological conditions.

The MSHA concluded that the operators were aware of the prevailing geological conditions and a previous burst.

However, the mine operator did not alter the retreat mining plan or take the logical steps that would have mitigated the likelihood of a coal or rock burst.

The mine operator did not revise the approved roof control plan when mining conditions and geological information indicated the plan was not suitable for controlling coal or rock bursts.

Two orders and two citations have been issued by the MSHA over the incident.