The Keystone mine is located at Keystone, McDowell County, on the line of the Norfolk & Western Railway; and operates in the Pocahontas No. 3 coal bed.

On the morning of July 2nd, the assistant mine foreman was conducting two men through the mine with the purpose of permitting them to select a place to work.

In conducting the men through the mine, he took them into the First Cross entry which had not been in operation for a number of weeks.  The entry had a number of heavy falls of the roof and to have resumed mining coal in this entry would have necessitated a week's time in which to remove the fallen material.  The entry was known to liberate explosive gas in small quantities, and to use an open lamp within the entry before making an examination with a safety lamp was well known to be ill advised.

In advancing up this entry the open lamp carried by the assistant mine foreman ignited the gas and an explosion followed which killed him and his two companions.  The explosive flame confined itself to the entry but the force of the expansion caused many stoppings to be blown down along the main entries, and the force was sufficient to tear off the wooden covering of an electric motor on the main entry and reduce it to many small fragments, one of which flying fragments struck the motor runner and penetrated his skull, causing his death four days later, thus making a total of four killed by the explosion.

The deceased:

• A. H. Medows
• Hillery Hall
• E. D. Howard
• William Mahan

Source:
	1907 Annual Report of the West Virginia Department of Mines