A young man or teenager drowned Friday in the Potomac River after apparently becoming trapped beneath a rock upstream from Great Falls, authorities said.

The death occurred not far above a 14-mile stretch that has been particularly deadly. But the number of drownings in that area had diminished in the past few years.

The victim was not identified immediately, but Montgomery County police said he was in his late teens or early 20s.

They said he apparently entered the water south of Riverbend Park, on the Virginia side, and waded to the middle of the river, where he became trapped.

Police are still investigating but said there was no immediate sign of foul play.