FILE – In this March 20, 2020 file photo, an empty baggage carousel spins in Denver International Airport as travelers deal with the spread of the coronavirus in Denver. Airline service in the United States is teetering on the brink of collapse, with near-empty planes and coronavirus-caused outbreaks that have left some air traffic control towers empty. Even with sharply reduced schedules, airlines are consolidating some of the remaining flights because passengers aren’t showing up. (AP Photo/David Zalubowski, File)