29 Apr April 29, 2016 by Critical Incident Team in Travel Alerts, United States Dozens of flights have been canceled at Denver International Airport because of rain and snow that began falling Friday morning. United Airlines canceled more than 70 flights at DIA, most of them regional flights. Most of Southwest and Frontier flights are taking off an arriving on time. Security lines were running a little slower than normal, the north lines were running about 20 minutes and the south lines were running about 30 minutes. The Concourse A bridge wait time is about 25 minutes.