Six people who died on 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 deaths of five men and a teenager on Aug. 20 shocked rural communities in and around Keenesburg, 35 miles (55 kilometers) northeast of Denver, where rescue workers entered an enclosed space to recover the bodies. Authorities immediately raised concerns that the deaths were linked to harmful gases.
The coroner's findings will inform an investigation by federal workplace safety and health investigators into what happened at the industrial-scale dairy plant owned by California's Prospect Ranch and what role a dairy equipment contractor played.
A heavy toll
Dairy operators and federal workplace safety regulators have said little about what went wrong.
The dangers of enclosed spaces on farms and dairies are a well-known and ongoing cause of death in agriculture in the United States – often from exposure to odorless and colorless noxious gases or from asphyxiation in enclosed spaces where oxygen is depleted.
All of those who died in Colorado were Latino men between the ages of 17 and 50. Four of them, including the teenage high school student, were from the same extended family.
As news of the deaths spread, people in the community organized fundraisers such as a dance, haircuts and a car wash to help the families of those who died. Several local churches organized a memorial service at the local fairgrounds in Keenesburg in early September, which included singing “Amazing Grace.”
“People are in shock. Everyone in the ranching and dairy industry knows it's difficult, hard work and accidents happen,” said the Rev. Thomas Kuffel, priest of Catholic churches including Holy Family in Keenesburg. “But this is very foreign to them because accidents typically involve one or two people.”
International impact
First responders from a rural fire district in Weld County were dispatched to Prospect Ranch around 6 p.m. Oct. 20 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.
According to Weld County Deputy Coroner Jolene Weimer, the Espinozas are related by marriage to another 36-year-old victim from Greeley – Jorge Sanchez Pena.
The other two men — Ricardo Gomez Galvan, 40, and Noe Montañez Casañas, 32 — lived in Keenesburg. According to Miguel Barradas Cerón of the Mexican Consulate in Denver, the remains of Montañez Casañas, a veterinarian working on a U.S. visa, were repatriated to the central Mexican state of Hidalgo.
Tight spaces and gases
Silos used to store grain and feed are among the deadliest enclosed spaces on farms, according to William Field, a professor at Purdue University who compiles annual reports on injuries and deaths. Hazards include gases from livestock feed that ferment and release carbon dioxide and nitrogen oxides.
The second most dangerous group of hazards is associated with the handling and storage of animal manure, which also includes hazards from harmful gases. When manure decomposes, toxic gases are released that can replace the available oxygen with carbon dioxide, methane, ammonia and the particularly toxic hydrogen sulfide.
Best safety precautions include access to self-contained breathing apparatus when oxygen is in short supply and emergency response planning and training, Field said.
“Having an emergency action plan – that would eliminate the cascading effects so that if someone fails, someone doesn’t just step in,” he said.
Supervision in the workplace
It can take six months or longer for the Occupational Safety and Health Administration to complete an investigation into workplace deaths and typically focuses on identifying root causes.
OSHA has launched inspections and investigations at Prospect Ranch, based in Bakersfield, California, and Fiske Electric, based in Johnston, Colorado, whose subsidiary High Plains Robotics services dairy equipment and employs several of the deceased workers. The companies have not publicly commented on what led to the deaths.
It is unclear whether the teenager was specifically used for dangerous work, although this would not be unusual or prohibited by law. Federal regulations allow people age 16 and older to perform hazardous work in agriculture, while the minimum age in other industries is 18 under the 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 do not provide detailed standards for confined space safety in the agricultural sector, even if permits are required.
Still, Anthony said, all industries, including agriculture, are required by federal law to keep workplaces free of recognized hazards that can cause death or serious injury.