The response was swift: White House reporters were swept off the north lawn and driveway and made to go into the West Wing. Police scrambled to guard the doors of the Senate chamber. Within minutes, two F-16s and two helicopters arrived on the scene.*
According to a security official, a single engine Piper Cub inadvertently strayed into the restricted airspace. The pilot was contacted and acknowledged his error. The plane has been diverted and is landing at an airfield in Maryland.
There were no evacuations, and the situation was effectively over by 1:00.
CBS News' Mark Knoller, Jill Jackson, Marc Ambinder, Kimberly Dozier and Bob Orr contributed reporting to this report.
*CORRECTION: This post initially incorrectly stated that two F-15s arrived at the scene. It was, as we've now noted above, two F-16s and two helicopters.