Carbon monoxide poisoning is being blamed for the deaths of a father and son from Utah on Flaming Gorge Reservoir on Monday.

Sweetwater County Sheriff's Department spokesman Dick Blust says 58-year-old Steven McConnell and his 17-year-old son, Matthew of Stansbury Park, Utah, were part of a group of ice fisherman and were sleeping in their own hut when they were found to be unresponsive at 9:00 a.m. A Rock Springs resident in the area contacted authorities, who responded to the scene and declared both McConnells dead.

Sweetwater County Coroner Dale Majhanovich says his investigation shows a  propane heater in the McConnell's hut emitted carbon monoxide, leading to their deaths. Blust says the tragedy should serve as a reminder that people using stoves, heaters and charcoal burners in closed spaces need to make sure they have proper ventilation.