Travelers across the country faced frustration and uncertainty as their plans were upended. At New York’s LaGuardia Airport, Janice Llewellyn feared missing her daughter’s wedding in Toronto. “I may lose my mind,” she said. In Las Vegas, passengers received conflicting information about the duration of the ground stop, with estimates ranging from eight to 24 hours. The lack of clear communication led to long lines at rental car counters as passengers sought alternatives.

Professional and college sports teams were also affected. NCAA teams were prioritized for rescheduling ahead of Saturday games, and Transportation Secretary Sean Duffy urged football teams to contact the FAA to secure flight times. Cargo flights were delayed as well, with FedEx activating contingency plans. U.S. airlines move about 61,000 tons of goods daily, according to Airlines for America.

The FAA attributed the ground stop to a telecommunications outage caused by new technology overloading older systems, not a cyberattack. Homeland Security Secretary Markwayne Mullin said there was no indication of a threat to national security. “It was overwhelming the older system,” he said. The FAA said flights were halted as an “abundance of caution” while en route traffic facilities recovered.

Aviation safety expert Steve Arroyo noted that the outage was similar to a September incident in the Northeast caused by a fiber optic line being cut, but this time it occurred on a nationwide scale. Transportation Secretary Sean Duffy warned that the U.S. air traffic control infrastructure is aging and prone to failure. “It’s going to continue to fail,” he said. The U.S. is in the middle of an overhaul of its air traffic control technology, and Duffy urged lawmakers for more funding.

A limited number of domestic flights resumed after the ground stop was lifted, but airlines warned it would take days to fully recover due to planes and crews being out of position. JetBlue Airways canceled the remainder of its Friday flights and some Saturday flights to allow crews and planes to be in place for resumption. The FAA said flights would be managed on a case-by-case basis, and airlines urged travelers to check for updates.

International flights were also affected, with two Cathay Pacific flights to Hong Kong delayed. The FAA said inbound international flights would be managed on a case-by-case basis. The disruption occurred just weeks before the Thanksgiving holiday, the busiest travel period of the year, and highlighted concerns about aging infrastructure and staffing shortages in the U.S. aviation system.