Passengers at Chicago’s O’Hare International Airport were forced to go through harrowing delays after a computer glitch at United Airlines check-in counter caused massive delays.

The computer outage occurred at the self-service check-in kiosks of United Airlines in the O’Hare Airport due to which the check-in services shut down unexpectedly. The outage resulted in thousands of flight passengers waiting in queues while half-empty airlines waited on the runway for its passengers. Several flights had to be canceled as delays snowballed and disrupted flight schedules and those that managed to take off were delayed by an average 45 minutes.

Chicago’s O’Hare International Airport were is a major hub of domestic as well as international flights which is why Thursday’s shutdown led to flights being cancelled or delayed at many other airports. United Airlines waived rescheduling costs for all passengers flying out of Chicago on Thursday and also encouraged customers to check in at its website.

Thursday’s outage at the O’Hare International Airport turned out be particularly inconvenient since this was the start of the Fourth of July weekend when travel picks up across airports. Even though this time is not as busy at the Thanksgiving of Christmas weekend, still families take off for vacations or family get-togethers.