Nationwide travel disruptions on Wednesday again snarled travelers flying in and out of Denver International Airport, where they were hit with a total of 245 delays and 81 cancellations as of 11:30 a.m., according to the FlightAware tracking service. United Airlines stood out, leading other airlines at DIA on Wednesday with the bulk of the problems: 78 cancellations and 137 delays, FlightAware data show. That brought United Airlines’ total at DIA over four days starting Sunday to 372 cancellations and 886 delays, the data show. Stranded passengers chafed.