Updated at 5:49 p.m. on Monday, Aug. 25, 2025.
The identities of the six Hispanic men killed last week after a suspected gas exposure at a dairy in Keenesburg have been announced by the Weld County coroner.
They were all from small communities around Fort Collins and Greeley and employed at Prospect Valley Dairy in Keenesburg. Their ages ranged from 17 to 50.
They have been identified as:
- Oscar Espinoza Leos, 17 of Nunn
- Carlos Espinoza Prado, 29, of Evans
- Noe Montanez Casanas, 32 of Keenesburg
- Jorge Sanchez Pena, 36, of Greeley
- Ricardo Gomez Galvan, 40 of Keenesburg
- Alejandro Espinoza Cruz, 50 of Nunn
Espinoza Leos was a student at Highland High School in Ault.
Four of the six were relatives: Espinoza Cruz is the father of both Oscar Espinoza Leos and of Carlos Espinoza Prado. Jorge Sanchez Pena is also related to the three by marriage.
Prospect Valley Dairy LLC is the owner of the farm. The company is based in Bakersfield, Calif. The Weld County coroner released a statement that said that all autopsies have been completed. The coroner’s statement says the incident was on Wednesday, Aug. 20, not Thursday as some outlets have reported.
The cause and manner of death are not yet confirmed, as the county is awaiting results of “further testing,” according to the county coroner’s statement.
The Greeley Tribune reported that “initial communications about the incident were reported as a burst pipe. On the scene, first responders noticed five men with possible high levels of H2S or hydrogen sulfide.”
One neighbor near the home of Espinoza Cruz’s house said that her son was best friends with the teenager, and that they were all grieving. She did not want to give her name and didn’t offer any additional comments, saying the family had found a lawyer and that she wanted to respect their wishes. Outside Espinoza Cruz’s house was what appeared to be a memorial, with candles surrounding a black truck parked out front, with a rosary on the grille.
Hydrogen sulfide occurs naturally in petroleum and in natural gas, and usually it only causes minor irritation to the eyes and the lungs, but exposure to large amounts in an enclosed space can become deadly, according to the article.
Oscar Espinoza Leos was, according to another student, a senior at Highland High School in Ault. Both a classmate and the school district said on Monday they were mourning his loss. He was “nice, outgoing, and kind,” said Brandon Franklin, a 16-year-old junior at the high school, which has 291 students serving Ault, Pierce, Nunn and Carr, all towns in northern Colorado.
The school’s district, Weld Re-9 School District, released a statement saying it “is deeply saddened to learn of the passing of a Highland High School student in a tragic confinement incident at a local dairy last Wednesday. This tragedy has deeply affected our school district and community.”
The school is making counseling available to students and teachers, according to the statement.
“Counseling and support services have been made available to students and staff alike, and the district is committed to continue providing assistance to those in need,” according to the statement. “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.”
The dairy farm is at the end of a long, flat road with silos, bales of hay, crop dusters and utility poles lining the streets.
Workers at the dairy would not comment. But a man in the office at the site, who refused to give his name or title, said the company was in contact with lawyers. He refused to give CPR News the name of the lawyers or contact information for them.
One other dairy worker, who was briefly interviewed, said he was working the day of the incident. Although the worker would not elaborate on what happened, other news outlets have reported that one worker entered an area with high amounts of a lethal gas, and that the other five who died went in after him in an effort to rescue him.
Editor's note: This story will be updated as additional information becomes available.
