WELD COUNTY, Colo. — The families of four dairy workers who died last year after exposure to high concentrations of a toxic gas inside a Keenesburg manure pit have filed a wrongful death lawsuit against the dairy, alleging its owner knew the system was failing months before the incident and did not properly fix it.
The complaint, filed Wednesday in Weld County District Court by the families of Jorge Sanchez Peña, 36; Alejandro Espinoza, 50; and his two sons, Carlos Espinoza Prado, 29, and Oscar Espinoza, 17, alleges that Prospect Valley Dairy and its owner, Arend Bos, had no gas monitors, no ventilation, no warning signs, and no rescue procedure or equipment when a manure pit pipe ruptured on Aug. 20, 2025, causing a total of six dairy workers to collapse and die from inhaling high concentrations of hydrogen sulfide.
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The lawsuit, which also names HD Builders, LCC as a defendant in the case, also alleges that Bos knew the pipes in the manure pit, “were unstable and not being adequately supported” before the incident.
“Specifically, before the incident, Prospect (Valley Dairy) resorted to using ratchet straps to hold parts of the piping system together immediately downstream of the pipe rupture because it was visibly unstable,” the lawsuit filed by the Cannon Law and The Spear Firm states.
Denver7 reached out to Prospect Valley Dairy and HD Builders LLC for comment but did not hear back by the time this story was published.
At the time of the accident, two separate sources in the dairy industry with knowledge of events told Denver7 that a worker who had finished contract repair work that day had gone back down into the pit to do some additional work and possibly “adjust a valve” when he accidentally turned on a valve or pump with his phone, causing the release of the toxic gas.
But according to the complaint, it was Bos, the owner, who remotely activated the system from his phone, causing a nearby pipe joint to rupture under pressure.
The complaint then alleges that Peña went into the pit to help a dairy employee close a valve and collapsed. When Espinoza and his two sons saw him go down, they ran in one after another to help and were overcome by the same invisible gas, the lawsuit states.
All four died in the pit, along with two dairy employees.
Weld County
These are victims of the deadly Colorado dairy accident in Keenesburg
The lawsuit also claims that besides the lack of gas monitors at the site, there were no signs warning people not to enter the pit in the event of a leak.
“This shouldn't have happened to these hardworking men who each ran in, one after another, trying to save the person before them,” said Sam Cannon, an attorney at Cannon Law who filed the lawsuit on behalf of the families. “Prospect (Valley Dairy) had every chance to fix what they knew was broken and chose not to. We intend to hold them accountable for that.”
Besides the lack of proper support in the manure management system, the complaint alleges Bos gave three conflicting accounts of what happened that day to the medical examiner, the fire department and to an insurance investigator, in which he ultimately acknowledged he had activated the system remotely and that the section of piping that failed was not part of the work the four men had performed that day.
“In failing to repair the unstable pipes, failing to warn contractors about the danger of (hydrogen sulfide), failing to provide (hydrogen sulfide) detectors, and failing to have a confined space entry plan, rescue plan, or rescue equipment in place, Prospect and Bos consciously disregarded a substantial and unjustifiable risk that a person would be killed by (hydrogen sulfide) in the pump pit,” according to the lawsuit.
In the complaint, the families accuse Prospect Valley Dairy of negligence and seek damages under Colorado’s wrongful death statue. The lawsuit also alleges the deaths constitute a felonious killing under Colorado law, which would remove the statutory cap on noneconomic damages.