🗞️ Six Dead, Three Companies Cited After Toxic Gas Fills Colorado Dairy Pump Room

On August 20, 2025, a disconnected pipe in the manure management system at Prospect Valley Dairy — operating as Prospect Ranch LLC — near Keenesburg, Colorado, released manure water and a surge of hydrogen sulfide gas into an enclosed pump room. Six workers died in a sequence that safety experts describe as a preventable cascading rescue pattern: one worker entered to stop the flow, was overcome, and subsequent workers entered to help, each succumbing to the gas. The Weld County Coroner confirmed all six deaths were caused by hydrogen sulfide exposure. The victims — Oscar Espinoza Leos (17), Carlos Espinoza Prado (29), Noé Montanez Casanas (32), Jorge Sanchez Pena (36), Ricardo Gomez Galvan (40), and Alejandro Espinoza Cruz (50) — included a father and two sons, one of whom was a high school student.

On February 24, 2026, the U.S. Department of Labor's Occupational Safety and Health Administration announced citations against all three companies with work crews on-site that day. Prospect Ranch LLC faces $132,406 in proposed penalties for failure to protect workers from atmospheric hazards, failure to maintain a written hazard communication program, and failure to train employees on methods to detect hazardous gases. Contractor Fiske Inc. — whose subsidiary, High Plains Robotics, services dairy equipment and employed four of the deceased — faces $99,306 for failure to protect employees from hazardous atmospheres and failure to provide hydrogen sulfide detection training. Contractor HD Builders LLC, whose employees were present but unharmed, faces $14,897 for failure to maintain a written hazard communication program and failure to train workers on H2S detection. The three companies have 15 business days to comply, request an informal OSHA conference, or contest the findings before the independent Occupational Safety and Health Review Commission.

In a public statement, Fiske Inc. and owner Kevin Fiske said the company disagrees with the findings and is reviewing its options, while affirming its commitment to preventing future tragedies. HD Builders declined comment.

The incident raises questions about the scope of agricultural worker protections under federal safety law. OSHA's Permit-Required Confined Spaces standard (29 CFR 1910.146) — which mandates atmospheric testing, ventilation protocols, rescue plans, and trained attendants before workers may enter enclosed spaces with atmospheric hazards — explicitly excludes agricultural operations. OSHA acknowledges the standard "serves as a guide" for farm work but is not enforceable in that sector. The cascading rescue fatality pattern observed at Prospect Valley Dairy — in which successive workers entered an unmonitored, unventilated space and were overcome — is the same pattern OSHA's 1993 confined space standard was designed to prevent in general industry. That standard has not been extended to agricultural operations. Hydrogen sulfide is among the leading causes of workplace gas inhalation deaths in the United States, is heavier than air, accumulates in low-lying enclosed spaces, and can incapacitate a worker within seconds at high concentrations.

Key Points

• A disconnected manure system pipe on August 20, 2025, released hydrogen sulfide gas into an enclosed pump room at Prospect Valley Dairy near Keenesburg, Colorado, killing six workers.
• The victims ranged in age from 17 to 50; four were members of the same family.
• OSHA cited three companies — Prospect Ranch LLC, Fiske Inc., and HD Builders LLC — for a combined $246,609 in proposed penalties for failures in hazard communication, atmospheric hazard protection, and H2S detection training.
• Fiske Inc. stated it disagrees with the citations and is reviewing its options; HD Builders and Prospect Ranch LLC did not immediately respond publicly.
• OSHA's Permit-Required Confined Spaces standard (29 CFR 1910.146), which governs entry into spaces with atmospheric hazards, does not apply to agricultural operations; the exemption has been in place since the standard was issued in 1993.
• The cascading fatality sequence — in which successive workers entered the space in attempted rescue — mirrors the pattern OSHA's 1993 general industry confined space standard was designed to prevent; that standard does not apply to agricultural operations.

Primary Source Author: U.S. Department of Labor, Occupational Safety and Health Administration

Primary Source: U.S. Department of Labor, Occupational Safety and Health Administration

Primary Source Link: https://www.dol.gov/newsroom/releases/osha/osha20260224-0

Supplemental Links

• https://www.osha.gov/hydrogen-sulfide — OSHA Hydrogen Sulfide Safety and Health Topics
• https://www.osha.gov/confined-spaces — OSHA Confined Spaces Overview
• https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.146 — 29 CFR 1910.146 Permit-Required Confined Spaces Standard (excludes agriculture)
• https://www.osha.gov/sites/default/files/publications/OSHA3939.pdf — OSHA Fact Sheet: Confined Space Entry on a Farm
• https://www.oshrc.gov/ — Occupational Safety and Health Review Commission
• https://www.denverpost.com/2026/02/24/prospect-valley-dairy-osha-fines/ — The Denver Post coverage
• https://www.washingtontimes.com/news/2026/feb/24/businesses-fined-government-6-deaths-colorado-dairy/ — Washington Times / AP coverage
• https://jordanbarab.com/confinedspace/2025/08/22/six-killed-in-confined-space-catastrophe/ — Jordan Barab: "Six Killed in Confined Space Catastrophe" (August 2025 policy analysis)