Your flight was canceled by the technology outage. What do you do next? WFTV [Video]

Air travelers became the face of the widespread technology outage Friday as they posted pictures on social media of crowds of people stranded at airports in Europe and the United States.

In the U.S., American Airlines, Delta Air Lines, United Airlines, Spirit Airlines and Allegiant Air had all their flights grounded for varying lengths of time. Airlines said the outage affected many systems, including those used to check in passengers, calculate aircraft weight and communicate with crews in the air. United, American and Delta issued waivers to let customers change travel plans.

By early evening on the East Coast, nearly 2,800 U.S. flights had been canceled and almost 10,000 others delayed, according to tracking platform FlightAware. Worldwide, about 4,400 flights were canceled.

Delta and its regional affiliates had canceled 1,300 flights, or more than one-fourth of their schedule, according to aviation-data firm Cirium. United and United Express canceled more than 550 flights, 13% of their schedule, and American Airlines’ network canceled more …