Six workers who died in August at a Weld County dairy were killed by exposure to hydrogen sulfide gas. That’s according to confirmation Thursday from the county coroner. Authorities say the men — ranging in age from 17 to 50 — were found dead on August 20th at Prospect Valley Dairy east of Keenesburg. The victims included 17-year-old Oscar Espinoza Leos, his father Alejandro Espinoza Cruz, and 29-year-old Carlos Espinoza Prado. They were among six relatives or coworkers overc