GREAT FALLS, Mont. (AP) — Cascade County sheriff's deputies and Great Falls police are searching for a man who disappeared while swimming in the Missouri River.

A witness called 911 at about 1:30 p.m. Tuesday to report the missing swimmer.

Sheriff Bob Edwards tells the Great Falls Tribune the missing man swam with his teenage son to a small island in the middle of the river. He says the two began to swim back, but the man went under as his son reached the shore.

Leah Marie Hoy says she saw her boyfriend's father struggling in the water and says he eventually started to move with the current.

She says she saw him disappear under the water.