The Brief Rescue crews found the body of a missing swimmer in the Potomac River on Thursday. The 25-year-old man went missing on July 28. Rescue crews recovered the body of a missing swimmer in the Potomac River on Thursday, just days after the man went missing. Third drowning in same stretch of Potomac River this summerThe backstory:The man's death marks the third tragedy in the exact same stretch of the Potomac River in just over a month. Potomac River regulationsThe other side:Authorities say they're working to warn the public about the dangers of the river, but enforcement across such a large area is a challenge.