The last day of the year-end holiday travel rush is unfolding like since  for airline passengers: chaotic.

Airlines canceled nearly 2,700 Sunday flights . across the country and into and out of the United States, according to flight tracker . That’s on top of more than 2,700 Saturday flight cancellations, bringing the total since Christmas Eve to more than 15,000 canceled flights. This weekend’s cancellations marked the worst two-day stretch of the holiday travel season and affected passengers on nearly every U.S. airline.

The travel trouble is expected to continue into Monday as an , with nearly 1,500 U.S. flights canceled as of late Sunday, according to FlightAware. Southwest Airlines has canceled nearly 400 Monday flights, or 10% of its scheduled flights, JetBlue 124 flights, or 12% of its flights.