DFW Airport ranked No. 1 on FlightAware's MiseryMap on Wednesday afternoon with the most cancellations and delays across all airports in the United States. American Airlines flyers said not enough gates were available or their flights were canceled.

The Federal Aviation Administration said American Airlines requested a ground stop for all of its flights for one hour early Tuesday, Dec. 24 due to a “vendor technological issue.” On top of that, thunderstorms are expected to roll in before noon. The Fort Worth area is already under a flash flood warning until 11:30 a.m.