Crews have found the body of a 25-year-old man who went missing in the Potomac River south of Great Falls earlier this week. He is the third person to die after swimming in that area of the river this summer. Montgomery County Fire and Rescue said its swift water rescue team found the man's body at 11:30 a.m. Thursday. Someone who jumped into the Potomac River to swim went missing, and someone with them called 911 and tried to help. Officials said the area where he went missing can get up to 50 feet deep.