The alleged second explosion took place in the gob area, after an original explosion on Labor Day, September 1, in the same area. The mine has been idle since the first explosion and will remain closed until the problem is solved.
About a dozen workers were repairing damage from the Labor Day explosion when the second blast took place, AP said. All the miners were safely evacuated from the mine without incident.
"We're back to square one and we still have a problem there," Terry Farley, state office of Miners' Health, Safety and Training, told AP. "Obviously we have some methane accumulating in the gob area and obviously there is an ignition source."
Farley told AP it would be difficult to identify the source of the explosion because it was located in the inaccessible waste area.
The company added the problem could be related to the ventilating system, which was damaged in the first explosion.
