The No. 5 mine was adjacent to the No. 1 Mine, which had been abandoned in 1980.  At approximately 2:30 p.m. on June 3, 1981, the No. 1 Mine was inadvertently penetrated by a continuous mining machine operator while he was working at a face in the second set of rooms in the adjacent No. 5 mine.

Immediately after, air suddenly rushed over the top of the mining machine, creating sounds which reportedly resembled those of a freight train.  Exclaiming "Let's get out of here, we have hit something," the continuous mining machine operator warned other section miners of the problem.

The entire section crew, except for two roof bolters, who remained unaccounted for, boarded a scoop to ride to the surface via the man trip route.  Soon after, however, the section foreman left the fleeing scoop to search for the two missing roof bolters.  Later that afternoon, the bodies of the foreman and the two roof bolters - all victims of asphyxiation - were recovered.

MSHA investigators determined that the section had been permeated by a sudden inrush of blackdamp (oxygen-deficient atmosphere) when the continuous mining machine unintentionally penetrated the abandoned adjacent No. 1 Mine.

This accident was caused by management's failure to require the drilling of boreholes in advance of the working faces.

Also contributing to the accident was a failure to accurately show the No. 1 Mine's workings on the mine map.

Source:
	Historical Summary of Mine Disasters in the United States - Volume II