MEDIMONT - A 52-year-old Osburn man ended up dying after his boat overturned on Medicine Lake Wednesday afternoon.

Dwayne Knapton died from his prolonged exposure to the 40-degree water, the Kootenai County Sheriff's Department said Thursday. The Press reported Thursday that Knapton was in critical condition at Kootenai Medical Center late Wednesday.

About 1 p.m. Wednesday, deputies responded to a boat wreck on the lake, which is near Medimont.

A passerby traveling along Highway 3 spotted two men clinging to a submerged 10-foot jon boat. The other man was Michael Jensen, 51, of Pinehurst.

Kootenai County Sheriff's Department Lt. Stu Miller said, "One (man) was much smaller than the other, and as such, more susceptible to the cold water."

The passerby called 911 and also flagged down an Idaho Department of Fish and Game officer.

Two Fish and Game officers launched an airboat into the lake and retrieved the men from the water.

Miller said the men were about 100 yards from shore.

The two had been duck hunting on the lake and at some point while retrieving a duck one of them shifted his weight, causing the boat to tip to one side.

Water poured into the boat, capsizing it. The two men, who had life jackets on board but were not wearing them, clung to the boat until they were rescued.

Jensen and Knapton were both hypothermic when they were taken from the water.

Knapton was taken by Medstar air ambulance to the hospital. Jensen was treated at the scene and released.

They had been in the water for an estimated 30 to 45 minutes prior to being rescued, the sheriff's department said.

It is unknown at this time if alcohol was a factor in the incident.