More than 2,000 flights were canceled Saturday as airlines across the U.S. worked to dig out from the longest nationwide ground stop in 25 years, which stranded passengers and forced professional and college sports teams to scramble for alternate transportation.

Trump administration officials said new technology being added to the nation's air traffic control system overloaded antiquated equipment and caused "intermittent" communications and radar gaps, leading to the flight shutdown of more than four hours.

A limited number of domestic flights departed after the stop was lifted around 8:15 p.m. ET. But the effects could be felt for days, with officials saying the system is likely to be operating normally in time to handle the Thanksgiving travel rush.