Compiled by Wayne Blanchard; last edit 4-8-2025 for upload to: http://www.usdeadlyevents.com/

–10 Cole, Jesse P. History of MSHA, slide 40.

–10 National Institute for Occupational Safety and Health, CDC. Mine Disasters.

–10 State Inspector of Coal Mines [CO]. Mine Disasters and Miscellaneous Fatal Accidents, 1923.

–10 United States Mine Rescue Association. Mine Disasters in the United States. Southwestern.

Narrative Information

National Institute for Occupational Safety and Health, CDC. Mining Disasters:

“05/051923 Southwestern Aguilar CO 10 [killed] Coal Explosion UG [underground]…”

State Inspector of Coal Mines [CO]. Mine Disasters and Miscellaneous Fatal Accidents, 1923:

“The following is my report concerning the explosion at the Southwestern mine, which occurred on the 5th of May, 1923, resulting in the death of ten men.

….

“The mine is situated about two miles northwest from the town of Aguilar, Las Animas county, Colorado, on the Colorado & Southern Railway. It is operated by the Rocky Mountain Fuel Co., of Denver. Colo. ….

“The seams being operated are the upper and lower Robinsons. explosion occurred in the lower seam, known as the North and South Slopes. The coal is bituminous, running from three to five feet in thickness. The coal is mined by hand. The ground is faulty. The mine is very dry, water very scarce and only available through purchase. The water for domestic use, outside hoist, and sprinkling of mine is pumped from Brodhead mine, a distance of one mile over the hills. Electric hoists were used for haulage purposes on inside slope and dip workings. Ventilation was produced by fan, electrically driven, producing about 40,000 CU. ft. of air per minute.

“Ordinarily there were between thirty and forty men employed in the mine, but on May 5th, 1923, the mine was idle. A few men were working, some cleaning haulage roads and others making coal for the next working day. As customary the fire boss had fired the shots and examined the mine prior to other employes going to work, and reported the mine in safe condition to the mine foreman, who visited the places where the men were working that morning, between nine and eleven a. m. On the morning of the explosion, fire boss record books showed mine clear of explosive gas from April 16th to May 4th, inclusive. The record book for May 5th had not been signed at this date, but was signed later showing mine clear of gas.

“From testimony given at the inquest it was stated that there were only three men at the mine who knew how to start the fan. The superintendent, mine electrician, and the mine blacksmith. According to the daily records of The Trinidad Power and Transmission Company, the power went off at 12:41 p. m., returning two minutes later, but owing to the volt release being thrown out, the

fan could not start until the release was thrown in. The superintendent being at dinner, about one-fourth of one mile distant, the electrician being in Denver, and the blacksmith being employed at

a point where he could not tell anything about the power, there was no one present who knew how to start the fan. The superintendent upon returning to the mine about 1 :20 p. m., being notified that the fan was not running, threw in the release. About three minutes later the explosion occurred.

“The Southwestern mine was examined by me on February 7th, J 923. I found numerous faults were being encountered, gas being given off at some of them, and while the mine had always been

an open light mine. I believed that on account of the faults, some of which were giving off explosive gas, the over-head cover getting greater, and the mine being dry, that Permissible Electric Head Safety Lamps should take the place of the open lights and so recommended. Mr. George Peart, upon receipt of recommendations advised by letter that electric head lamps would be installed. This recommendation had not been complied with at the time of the explosion. Mr. George T. Peart, Assistant General Manager for the company, produced letters at the inquest stating that electric head lamps had been ordered from the Mine Safety Appliances Co., of Pittsburgh, Pa., and that no assurance could be given as to the date of delivery by the manufacturers. In the meantime the coal company had some electric lamps brought from some of their other properties, but many of the batteries were found defective, and only a few of them in working condition, which were given to the men working in the most dangerous places in the mine….” (pp. 71-72)

Cause of Explosion

“The explosion was caused: first, by the power being cut off the mines by a flash of lightning. Second, by no one being present that knew how to start the fan immediately upon return of power, thereby allowing fan to remain idle for thirty to forty minutes, sufficient to allow considerable explosive gas to accumulate, that upon starting of fan, gas was carried to and came in contact with an open light, exploding, thereby raising the coal dust in suspension causing a general explosion of gas and dust that traversed the whole mine.” “Respectfully submitted, Hugo H. Machin.” (p.74)

Newspaper

May 12, Eagle County News, CO. “Explosion Kills Ten.” 5-12-1923 Transcribed by USMRA:

“Trinidad, Colo. — Ten bodies of the miners have been removed from the Southwestern mine of the Rocky Mountain Fuel Company in the Aguilar district, which was the scene of a gas explosion.

….

“The dead are: [We place the names into separate lines.]

Leon Cordova,

John Konistakis,

John Souaginis,

Chris Katelels,

Candelaro Trujillo,

Tony Bozman,

Roy Gallegos,

Luke Lucero,

Alex Johnson,

P. McKenna….”

Sources

Cole, Jesse P. (MSHA District 4 Manager). “History of MSHA,” Leadership Intensive Course Mine Safety and Health Administration. No date. 48 slides. Accessed 1-11-2009 at: http://www.usmra.com/repository/category/mining/modified_History_of_MSHA.ppt#256,1

Eagle County News, CO. “Explosion Kills Ten.” 5-12-1923 Transcribed by USMRA. Accessed 4-9-2025 at: https://usminedisasters.miningquiz.com/saxsewell/southwestern.htm

National Institute for Occupational Safety and Health, Mining Safety and Health Research. Mining Disasters (Incidents with 5 or more Fatalities). NIOSH, Centers for Disease Control and Prevention, 2-26-2013 update. Accessed 4-9-2025 at:

https://wwwn.cdc.gov/NIOSH-Mining/MMWC/MineDisasters/Table

State Inspector of Coal Mines [CO]. Mine Disasters and Miscellaneous Fatal Accidents, 1923. Accessed from United States Mine Rescue Association photocopy 4-9-2025 at: https://usminedisasters.miningquiz.com/saxsewell/1923_Southwestern_Report.pdf

United States Mine Rescue Association. Mine Disasters in the United States. “Rocky Mountain Fuel Company Southwestern Mine Explosion, Aguilar, Las Animas County, Colorado, May 5, 1923, No. Killed – 10.” Accessed 4-9-2025 at: https://usminedisasters.miningquiz.com/saxsewell/southwestern.htm

1923 – May 5, Southwestern Coal Mine gas explosion, Aguilar, Colorado — 10