Updated 7:30 p.m.
An earlier report that a person was planning to jump from the Key Bridge appears to have been a false alert. Both Arlington and D.C. officials confirmed that no person was located in connection with the incident.
Arlington County Detective Crystal Nosal said the individual did speak with Arlington's 911 dispatch, but that the Key Bridge is D.C.'s domain.
D.C. Fire and EMS Spokesperson Pete Piringer said there was "nothing found" when teams reported to the scene.
A person is threatening to jump from the Key Bridge that spans the Potomac River between Arlington and Georgetown.
According to sources, the Arlington County 911 is on the phone with a person claiming they are on the Key Bridge and going to jump. The D.C. Fire Department has dispatched a full water rescue assignment and police from D.C. and Arlington are responding.