The combination method of mining in this mine involved the caving of the capping.  The capping over what was known as the northwest ore body, which was about ready for caving, had given warning on April 16 that a collapse was imminent by the increased amount of cracking and slabbing off of ground.

For this reason the men were kept out of that part of the mine which was expected to be affected by caving.  When the fall came on the following day, a tremendous compressive force was exerted throughout the mine workings.

It was estimated that 3,500,000 cubic feet of air was displaced.  The air pressure was irresistible; men and equipment were thrown about, and in the open workings, where the rush of air was greatest, the effect was especially disastrous.  Five men were killed and 16 were injured, but nobody was caught directly under the cave.

The deceased:

• Drago Andesillo, 29
• Charles Cox, 29
• Nick Martinovich, 29
• Manuel Naredo, 29
• J. B. VanOrder, 29

Source: Arizona Mining Accidents, 1904-1998