CHICAGO, US - NOVEMBER 13: A view of an information board at the Chicago O'Hare International Airport, filled with waiting passengers on November 13, 2026, after the Federal Aviation Administration ordered a nationwide ground stop on all departing flights following a communication issue impacting air traffic control centers across the United States. With departures held until further notice, travelers waited in crowded terminals as delays mounted, while arriving flights continued to land normally. (Photo by Jacek Boczarski/Anadolu via Getty Images) | Anadolu via Getty Images At a press conference today, Transportation Secretary Sean Duffy said that Friday's nationwide ground stop ordered by the FAA was related to work replacing outdated copper wire with a fiber optic line at a "remote FAA facility." The secretary said that this was "routine maintenance," rather than the result of a major modernization effort. He told reporters that it was "such an old wire that it was being discontinued, meaning that line was going to get shut down," necessitating the upgrade.