Elk Creek subsequently reduced its output following a pillar burst
that led to an increase in ethane and fire.
Federal officials have released findings from an investigation into a May pillar burst that killed two miners, blaming the operator for a failure to recognize and control potential rib burst conditions.
The Mine Safety and Health Administration (MSHA) said that the pillar burst caused an ejection of coal into the mine entry, filling it to within 30 in.
The inspector, Stephen Falk, warned that attempting to remove coal from the pillars that held up the mine roof would "result in hazardous mining conditions such as pillar bursts
and roof fails," which is, of course, exactly what happened last August.