Six people who died at a Colorado dairy farm this summer were exposed to hydrogen sulfide gas, authorities said Thursday.
The Weld County coroner's office drew its conclusions from autopsies and toxicology tests.
The on Aug. 20 sent in and around Keenesburg, 35 miles (55 kilometers) northeast of Denver, where emergency responders entered a confined space to recover the bodies. Authorities had immediately expressed concern that the deaths were linked to harmful gases.
The coroner's findings will factor into an investigation by federal workplace safety and health investigators into determining what happened at the industrial-scale dairy, owned by California-based Prospect Ranch, as well as the role of a dairy equipment contractor.
The autopsy reports gave no indication of the circumstances of the deaths, describing only an industrial accident in a confined space at a dairy farm.
What happened at the dairy farm
Dairy operators and federal workplace safety authorities have said little about what went wrong.
The hazards of confined spaces on farms and dairies are a well-known and persistent cause of death in agriculture across the U.S. — often from exposure to odorless and colorless noxious gases, or due to asphyxiation in closed spaces where oxygen has been depleted.
All those who died in Colorado were Latino, ranging in age from 17 to 50. Four of them, including the teenage high school student, were from the same extended family.
As the news spread of the deaths, people in the community organized fundraisers including a dance, haircuts and a car wash to benefit the families of those who died. Several local churches organized a memorial gathering at the local fair grounds in Keenesburg in early September that included singing “Amazing Grace."
“People are in shock. Everybody in the ranching and dairy community knows it’s difficult, hard work and there are accidents,†said the Rev. Thomas Kuffel, a priest at Catholic churches including Holy Family in Keenesburg. “But this is very foreign to them, in that accidents are typically one or two people.â€
Who are the people that died
First responders from a rural fire district in Weld County were dispatched around 6 p.m. on Aug. 20 to Prospect Ranch and took their own safety precautions as they entered a confined space.
Alejandro Espinoza Cruz, of Nunn, was found dead along with his 17-year-old son Oscar Espinoza Leos and a second son, 29-year-old Carlos Espinoza Prado of Evans.
The Espinozas are related by marriage to a 36-year-old from Greeley who died — Jorge Sanchez Pena, according to Jolene Weiner, chief deputy county coroner for Weld County.
The other two men — Ricardo Gomez Galvan, 40, and Noe Montañez Casañas, 32 — lived in Keenesburg. The remains of Montañez Casañas, a veterinarian who was employed under a U.S. visa, were repatriated to the central Mexican state of Hidalgo, according to the Mexican consulate in Denver. Relatives of those who died couldn't immediately be reached.
Why confined spaces are dangerous
Silos that store grain and feed are among the most deadly confined spaces on farms, with hazards that include gases from fodder for feeding cattle that ferments and releases carbon dioxide and nitrogen oxide, according to William Field, a professor at Purdue University who compiles annual reports on injuries and fatalities.
The next most deadly group of hazards are associated with the handling and storage of animal manure, which also include dangers from harmful gases. As manure decomposes, it releases toxic gases that can replace available oxygen with carbon dioxide, methane, ammonia and hydrogen sulfide.
Hydrogen sulfide is a highly toxic gas that is colorless but has a sulfurous smell reminiscent of rotten eggs.
After some exposure, people can quickly lose the ability to smell the gas even though it’s still there through “olfactory fatigue.†At high concentrations, the ability to smell the gas can be lost instantly, according to the Occupational Safety and Health Administration.
Proven safety precautions include access to a self-contained breathing apparatus with a short supply of oxygen and emergency response planning and training, Field said.
“Having an emergency action plan that would eliminate the cascading effects, so that if somebody is down, somebody doesn’t just jump in there,†is important, he said.
What workplace oversight was there
OSHA can take six months or longer to complete an investigation into workplace fatalities and typically focuses on identifying root causes.
OSHA has launched inspections and investigations of Prospect Ranch as well as Johnstown, Colorado-based Fiske Electric, whose subsidiary High Plains Robotics services dairy equipment and employed some of those who died. Prospect Ranch could not be immediately reached for comment, and Fiske Electric did not respond to email and phone messages.
The progress of the investigations is unclear. Local, regional and Washington, D.C.-based representatives for OSHA did not immediately respond to phone calls and emails on Thursday. Automated responses said no one could reply because of the .
It’s unclear if Espinoza Leos, the teenager, was assigned specifically to hazardous work, though that wouldn’t be unusual or prohibited by law. Federal regulations those who are 16 and older to do hazardous jobs in agriculture, while the minimum age is 18 in other industries, under child labor provisions of the Fair Labor Standards Act.
Renée Anthony, an environmental engineer and director of the Great Plains Center for Agricultural Health at the University of Iowa, said federal regulations leave out detailed standards for confined space safety in the agriculture sector even where permits are required.
Still, Anthony said all industry sectors, including agriculture, have an obligation under federal law to keep workplaces free from recognized hazards that can cause death or serious injury.
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This story has been updated to correct the date of the deaths to Aug. 20 and the spelling of the last name of Jolene Weiner.
