6 Colorado Dairy Workers Killed by Toxic Gas Exposure

OSHA penalizes dairy owner and contractors over deadly manure pipe accident

Published on Feb. 25, 2026

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Federal workplace safety regulators have penalized three businesses over their failure to protect six Colorado dairy workers who were killed by exposure to highly toxic hydrogen sulfide gas after a manure pipe disconnected in an enclosed space. The U.S. Occupational Safety and Health Administration announced proposed fines totaling $246,609 against the dairy owner, Prospect Ranch LLC, and two contractors working on the manure management system.

Why it matters

The hazards of confined spaces on farms and dairies are a well-known and persistent cause of death in agriculture across the U.S. This incident highlights the need for better safety protocols and training to protect workers from exposure to noxious gases in enclosed agricultural environments.

The details

The deaths of five men and a teenager on Aug. 20, 2025 occurred after a manure pipe disconnected, releasing manure water and the deadly hydrogen sulfide gas. A Fiske employee and a Prospect Ranch employee tried to stop the flow but were overcome by the gas. Subsequently, three more Fiske employees and one Prospect Ranch employee entered the pump room, leading to the loss of all six workers.

  • On August 20, 2025, six Colorado dairy workers were killed by exposure to hydrogen sulfide gas.
  • On February 25, 2026, OSHA announced proposed fines totaling $246,609 against the businesses involved.

The players

Prospect Ranch LLC

The dairy owner, facing the largest fine of $132,406 for serious violations including failures in training, planning and protecting workers from atmospheric hazards.

Fiske Inc.

A Colorado-based contractor hired to work on the manure management system, facing $99,306 in penalties for failing to protect employees and provide hydrogen sulfide detection training. Fiske Inc. employed four of the workers who died.

HD Builders

Another contractor hired to work on the system, cited for failing to have a written hazard communication program and provide training on detecting hydrogen sulfide, with a proposed $14,897 penalty.

Alejandro Espinoza Cruz

One of the victims, found dead along with his 17-year-old son Oscar Espinoza Leos and 29-year-old son Carlos Espinoza Prado. They were from the same extended family and worked for Fiske Inc.'s High Plains Robotics.

Noe Montañez Casañas

One of the victims, a 32-year-old veterinarian employed under a U.S. visa whose remains were repatriated to the central Mexican state of Hidalgo.

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What they’re saying

“Our hearts are heavy as we review OSHA's citations. We have cooperated with the investigation proceedings to date. While we disagree with the findings and are reviewing our options to determine next steps, we are focused on doing what is in our power to ensure that a tragedy like this never happens again.”

— Kevin Fiske, Owner, Fiske Inc. (dewittdailynews.com)

What’s next

The companies have 15 days to comply with proposed penalties, request an informal conference with safety regulators or challenge the findings before an occupation safety review commission.

The takeaway

This incident underscores the critical need for improved safety protocols and training in the agricultural industry to protect workers from the hazards of confined spaces and exposure to toxic gases. Regulators must continue to enforce strict safety standards to prevent future tragedies like this one.