BRITTON, S.D. (KWAT) — The South Dakota Game, Fish and Parks Department and Marshall County Sheriff’s Office are investigating a drowning on a northeast South Dakota lake.

GF&P District Supervisor Tim McCurdy says it happened last Thursday night, around 6:15 p.m., on South Red Iron Lake, between Sisseton and Britton.

McCurdy says two brothers were in a fishing boat when the boat began taking on water and capsized.

One of the men was able to swim to an island while dragging his brother with him.

A Marshall County deputy was first to arrive on the scene, and performed CPR on the one man who was unconscious. Those efforts were unsuccessful and he was pronounced dead at the scene.

The second man was treated at the scene for hypothermia.

The man who drowned is identified as 47 year-old Jesse Paul Skarnagel of Claire City.

McCurdy says an autopsy is being performed by the Marshall County Coroner to confirm drowning as the cause of death.

Water temperatures were very cold, in the mid 40s, and Skarnagel was wearing heavy bib overalls, which made swimming difficult.

McCurdy says there were life jackets in the boat, but they were not being worn.