Six people in Northeast Colorado died last week after what’s being described by officials as a “dairy accident” at Prospect Valley Dairy. One of the deceased was a student in the Weld School District. Three other people were taken to a local hospital and released. Officials report the deaths were due to hydrogen sulfide exposure in a confined space due to a pipe leak. The Occupational Health and Safety Administration says hydrogen sulfide occurs naturally in crude petroleum and natural gas, but is also produced by decomposing manure. It’s mildly irritating to people’s eyes and respiratory systems when exposed to it in low doses, but it can quickly become deadly when people are exposed to large amounts in a confined space. The Weld County Coroner’s Office said that all the victims were male. The property is owned by Prospect Valley Dairy LLC and lists a Bakersfield, California, address for the owners.