All flights into and out of one of the United States’ busiest runways were halted for a time Tuesday due to a bomb threat, federal authorities announced. The threat was directed towards a United Airlines flight traveling from Houston, Texas, to Ronald Reagan National Airport in the Washington, D.C., area, U.S. Department of Transportation Secretary Sean Duffy said on X. All other flights were put on hold while the aircraft was moved to an isolated area of the airfield and the passengers