MINNEAPOLIS — Three teenagers from a church group were rescued from rushing water after they lost control of their canoe in rapids at the top of a waterfall on the U.S.-Canada border in northern Minnesota, with one of them becoming trapped by the damaged boat for several hours, authorities said Wednesday.

The 15-year-old boy was nearly unconscious during the last half-hour of the rescue in the Boundary Waters Canoe Area Wilderness, the Lake County Sheriff’s Office said in a statement. He had extreme hypothermia and a leg injury.

The sheriff’s department said it received a call around 1 p.m. Tuesday about the accident, which happened between 10:30 a.m. and 11:30 a.m. on the Upper Basswood Falls, which have a drop of 25 to 30 feet. The damaged canoe was pinned against the rocks by the force of the rushing water, trapping the 15-year-old, the statement said.

Rescuers from the Lake and St. Louis County sheriff’s departments reached the group around 3 p.m. and freed the trapped youth about 5:15 p.m. The other two boys in the canoe were OK, Sheriff Casey Johnson said.