Accidental carbon monoxide poisoning is what killed a 21-year-old Bemidji man last week in a fish house on Leech Lake, the Ramsey County Medical Examiner’s Office said Tuesday.

Cass County sheriff’s deputies were called to the fish house about 9 a.m. on Feb. 25 during the International Eelpout Festival. Samuel Schooley was taken to the Park Rapids hospital unconscious and pronounced dead, the Sheriff’s Office said.

According to an online obituary, Schooley graduated from Waconia High School in 2015, then earned a degree in carpentry from Ridgewater College in Willmar. His funeral was held last week in Waconia.

The Eelpout Festival, held annually for four days in Walker, attracts thousands of visitors.