Why Were All West Coast Planes Grounded Yesterday for 15 Minutes?

THE MYSTERIOUS WEST COAST ORDER FOR PLANES TO BE GROUNDED

ALEX STONE, ABC NEWS CORRESPONDENT, (Inteview length 3:47)

We are trying to get details on a mysterious brief West Coast ground stop for all aircraft yesterday around the time that North Korea tested a missile. All aircraft were told there was a ground stop and to remain on the ground or head toward an airport. And then quickly it was cancelled. As of this writing the FAA has not explained what happened. NORAD says it did not issue any kind of alert about any danger to the United States. Pilots, airports, and others are seeking answers today from the FAA.