The U.S. Park Police had sent its two helicopters to assist with operations at the Pentagon. Shortly thereafter, the flight control tower at Ronald Reagan Washington National Airport was evacuated. Flight control of all airspace over the Washington metro area was turned over to the U.S. Park Police helicopters who coordinated with NORAD. However, needing to assist with evacuating victims, the Park Police requested assistance from MPD. Shortly thereafter, an MPD helicopter arrived and took over command and control of Washington's air space.