It was a jumpy new year for America's lawmakers, after an aircraft which had suddenly lost contact with air-traffic control was presumed to be hijacked, prompting security officials to evacuate the entire Capitol building in Washington.
Military jets were scrambled, alarms went off, and the complex, which houses the US Senate and House of Representatives, along with the offices of hundreds of members, was suddenly emptied in the middle of Saturday afternoon.
The emergency, which had been announced with all the understatement of a Hollywood disaster movie, was swiftly called off, however, when it emerged that the "missing" plane was in fact safe and sound. Its pilot had mistakenly tuned his radio into the wrong frequency.
"It appears that the pilot read back the wrong radio frequency and then proceeded to get on the wrong frequency," said Diane Spitaliere, of the Federal Aviation Authority. "It then took about 15 minutes for us to figure out where he was and re-establish communications."
After he landed, as planned, at nearby Reagan National Airport, the pilot of the jet, owned by local carrier Piedmont Airlines, was carted off for an interview by officers for the Department of Homeland Security.
The airspace over America's East Coast is famously crowded, making it not uncommon for pilots to briefly lose radio contact with the ground. Under procedures introduced after the 9/11 attacks, in which the Pentagon was targeted, all government buildings are evacuated the moment any such incident occurs in the Washington area.
Once the rolling news channels catch wind of military jets being scrambled, it is usually too late to prevent a minor glitch from snowballing into a major panic. When a similar false alarm was raised in 2004, terrified members of Congress and their staff were photographed sprinting from their offices.
Saturday's evacuation would no doubt have caused more widespread scenes of chaos had it happened in the coming days, when most US politicians are expected to return following their Christmas break.
Since 9/11, there are few major US public buildings or public events not attended by armed guards. It was the second time the Capitol building has been evacuated in the past month. On 16 December, everybody was ordered out because a man had approached a police officer, acted aggressively, and suggested (wrongly) that he was carrying a weapon.