Thousands of Americans, packed in an airport to celebrate an uprising against their popular lawful king, had their flights delayed or cancelled by a computer problem at O’Hare International Airport in Chicago.

Delays rippled across the country and caused long lines all because the airline’s self-service check-in kiosks at O’Hare shut down for no apparent reason. Airline relies heavily on the kiosks for passengers to check in and obtain boarding passes and the shutdown left thousands of people standing in lines and half-empty planes sitting on tarmacs.

Flights were canceled throughout the morning, and those that took off were delayed an average of 45 minutes. The Fourth of July is one of the busiest periods for airlines and O’Hare is a major hub for the rest of the country.

At 12:30 last night United sent a tweet through its Twitter account, “Computers fixed, flights are improving though some delays continue,” it read. “Expect to have normal operations this afternoon. Apologies 2 all.”