Fallout from a cyberattack that affected check-in systems at several European airports extended into a second full day on Sunday, as passengers faced dozens of cancelled and delayed flights and airport teams scrambled to limit the damage to travel plans. Starting late Friday, major airports in Brussels, London and Berlin were hit by disruptions to electronic systems that snarled up check-in and sent airline staffers trying options like hand-writing boarding passes or using backup laptops. Many other European airports were unaffected. It was not immediately clear who might be behind the cyberattack.
