Company spokesperson Ted Pile told ILN that a section of roof measuring 60 feet in length and 17-20ft in height had fallen in an area of the mine developed 12 years ago which was no longer actively worked.

“This area now serves only as a corridor for the transportation of coal, supplies and ventilation [and] is examined routinely,” he pointed out, adding that about 60ft of belt and structure there received the brunt of the impact.

“We required no assistance from the OEMs and no other equipment was damaged.”

The incident occurred Wednesday and was made public Friday.

About 30% of Emerald’s 560-worker crew is onsite addressing issues such as remediation and cleaning of the area, installation of additional roof supports, maintenance and repair work, and other tasks required so production can resume.

Alpha president Kurt Kost said coal should be cut once again in about two weeks.

"The most important thing is that no one was injured in this incident,” he said.

“Since the Emerald mine has adequate coal inventory, we do not expect any disruptions to customer deliveries during the time it takes to repair the conveyor, nor do we expect that this event will have a material impact on our financial results during the quarter."

Emerald, a longwall mine, extracts from the Pittsburgh 8 seam and has an annual capacity of about 6 million tons.