A lawsuit filed in Weld County alleges that inadequate pipe supports and missing safety measures contributed to the deaths of six workers at a Keenesburg dairy after a manure-system pipe ruptured and released toxic gas in August 2025. The complaint, filed Aug. 19, 2026, names Prospect Valley Dairy LLC, Prospect Ranch LLC, dairy owner Arend Bos and contractor HD Builders LLC. It was brought on behalf of family members of three of the workers. Attorney Sam Cannon, who represents families of four of the six men, says the deaths could have been prevented. The lawsuit says workers were repairing piping in a manure pit about 12 feet deep. After the work, Bos restarted the system remotely using a phone app, according to the complaint. A pipe burst, releasing hydrogen sulfide gas. One worker entered the pit to reach a valve and collapsed; others went in to help and were also overcome, the filing says. The workers who died were Carlos Espinoza Prado, 29, of Evans; Noe Montanez Casanas, 32, of Keenesburg; Jorge Sanchez Peña, 36, of Greeley; Ricardo Gomez Galvan, 40, of Keenesburg; Alejandro Espinoza Cruz, 50, of Nunn; and Oscar Espinoza Leos, 17, of Nunn. Espinoza Leos was a high school student. The victims included a father and two sons, and several were related by blood or marriage. The complaint alleges the pit lacked gas monitors and alarms, forced ventilation, confined-space entry procedures, warning signs and rescue equipment. It also points to inspection photographs showing pipes supported by ratchet straps, which the filing says were not designed to hold pipes against pressure. Occupational medicine specialist Robert Harrison said confined spaces require precautions such as air testing, appropriate breathing equipment, a worker monitoring those inside and a rescue plan. Hydrogen sulfide can be fatal, making safeguards especially important when workers enter areas where the gas may accumulate. Bos’s attorney, Michael O’Donnell, has said the owner relied on the expertise of contractors hired to repair the pump system and intends to defend against the claims. O’Donnell said Bos restarted the system only as directed by the repair experts, and denied that the dairy caused the system to fail. The U.S. Department of Labor’s Occupational Safety and Health Administration cited three companies after investigating the deaths and issued fines totaling about $250,000 in February 2026. OSHA said workers were overcome after entering the pump room during the incident. The penalties were appealed, Cannon said, though he said he lacked access to records confirming the status of those appeals. The families say their relatives rushed into danger to help others. In a statement released through Cannon, they said they brought the lawsuit to seek accountability and prevent another family from experiencing a similar loss.