SAUK CENTRE — Authorities said a buildup of hydrogen sulfide gas at a farm near Sauk Centre killed around 50 pigs and sent two workers to the hospital.

Stearns County Sheriff Don Gudmundson said two employees at Fiedler Finishing were working inside the pig barn all day Wednesday, agitating and pumping manure, when they found about 50 dead pigs. They opened the curtains on the barn to ventilate the affected area but became ill from the hazardous fumes.

The two workers — 27-year-old Robert Alverson, of Osakis, and 31-year-old Bradley Kettering, of Glenwood — were treated at the Sauk Centre hospital.

The farm’s owner, Paul Fiedler, of Sauk Centre, told authorities the barn contained around 5,000 pigs, and it didn’t appear that any other animals were harmed.