Four of the six people found dead this week from a potential gas exposure at a Weld County dairy were members of the same extended family, including a high school student, according to a workers advocate and a fundraiser set up by a relative.

Local and federal authorities on Friday continued to investigate the deaths at Prospect Valley Dairy, 32063 Weld County Road 18, east of Keenesburg, but offered few new details about what happened. Officials previously called the Wednesday incident a possible gas exposure in a confined space.

Jolene Weiner, chief deputy county coroner, on Friday evening confirmed the identities of the six victims as 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. The coroner’s office completed the autopsies by Friday evening, and the determinations of the causes of death are pending as officials await the results of testing.

Jeff Platt, a communications manager with online fundraising platform GoFundMe, confirmed that four of the deceased were connected to a Greeley man named Juan Mendez, who organized a fundraiser to pay for the men’s funerals.

Platt identified one of the victims as Mendez’s father and three others as relatives of Mendez’s sister-in-law. Alejandro Espinoza was the father of Oscar Espinoza, who had attended Highland High School in Ault, Platt said.

A friend and coworker set up a separate GoFundMe campaign for Noé Montanez Casanas later on Friday, according to Platt.

The four family members worked on machinery repair at various dairies in the area, said Ana Schultz, who leads a team of outreach workers for Project Protect Food Systems Workers, a support network for food workers.

“From my understanding, they had worked at dairy farms for a really long time,” said Tomi Rodriguez, another Project Protect outreach worker: “They were extremely hardworking and humble. They were a very united family.”

The other two individuals lived on the dairy farm’s grounds in employer-provided housing, she said.

The Weld Re-9 School District, which confirmed Thursday night on Facebook that one of the victims had attended Highland High, said students and workers would have counseling and support services made available to them. Platt said Oscar Espinoza had attended Highland High in person last year but recently switched to online courses.

“This tragedy has deeply affected our school district and community,” the Weld RE-9 social-media post said. “Our thoughts are with the student’s family and friends during this difficult time, and we extend our sincere condolences to all who are impacted by this loss.”

Local and federal investigations

The six deaths are the subject of investigations by both the Weld County Sheriff’s Office and the federal Occupational Safety and Health Administration.

Sheriff’s spokeswoman Melissa Chesmore said the office is investigating whether any crimes were committed leading up to the men’s deaths. As of Friday morning, the office’s investigation had not revealed anything criminal in nature, but she said no other information could be released.

OSHA officials wrote in a Friday morning email that they would not release information until the agency’s investigation was complete. The email noted that OSHA has six months to complete its investigation.

About 6 p.m. Wednesday, the Southeast Weld Fire Protection District responded to a call for a confined-space rescue at the dairy. Once on the scene, crews found six people dead.

Initial radio communications about the incident reported a burst pipe. At the scene, first responders noted five men with possible high levels of H2S, or hydrogen sulfide, according to archived radio transmissions.

OSHA stated that hydrogen sulfide occurs naturally in crude petroleum and natural gas, but is also produced from decomposing manure.

The owners of the dairy have not publicly addressed the deaths and can’t be reached.

County tax records say the property is owned by Prospect Valley Dairy LLC and list a Bakersfield, Calif., address for the owners.

The farm has a 32,500-square-foot dairy milking parlor as well as two free stall barns, one built in 2017 that is more than 450,000 square feet and another built last year that is more than 100,000 square feet.

‘We are calling for stronger safeguards’

The incident in Weld County comes a year after a similar tragedy at a sugar plant in Fort Morgan.

In May 2024, one person died and four were hospitalized after being exposed to toxic hydrogen sulfide gas at the Western Sugar Cooperative.

Employees were performing routine maintenance at a utility building near the sugar plant when they were “unexpectedly exposed” to “naturally occurring” hydrogen sulfide fumes, a company executive told Colorado Public Radio at the time.

A subsequent OSHA investigation found multiple Western Sugar workers were exposed to the gas, which had been emitted from a pipe containing water with byproducts from sugar beets, dirt, mud and chemicals used in water treatment.

Federal investigators found 11 “serious” violations and issued the cooperative more than $168,000 in fines. The company ended up settling with OSHA, accepting $59,917 in penalties.

The Colorado Department of Public Health and Environment said it is not aware of any state certifications or training required for people who work in areas with potential high exposure to hydrogen sulfide.

The state agency only inspects the production of milk to ensure it’s a safe product, in addition to monitoring air and water quality standards.

The Fort Morgan and Weld County incidents “serve as an urgent reminder that agricultural work in Colorado can be deadly if we don’t have stronger, enforceable safety protocols,” said Hunter Knapp, development director for Project Protect.

“We know that these dangerous conditions exist in many industrial farming settings due to the accumulation of waste by-products,” he said in an email. “Unfortunately, confined spaces, manure pits and other by-products of large-scale operations can create deadly risks if not managed properly. That’s why we are calling for stronger safeguards, consistent enforcement and culturally appropriate training to ensure that workers are protected across Colorado’s farms and food facilities.”

Thus far, Knapp said, there has been no action by state or federal regulators.

The Associated Press contributed to this report.