The delays were caused by a nationwide system outage.
A team from Eyewitness News was at Hobby International Airport when passengers were told they could not board their flight due to the breakdown and will be updated every 10 minutes.
In a statement to ABC News, Southwest apologizes for any inconvenience: “Some of our first outgoing flights were delayed this morning, and a handful were canceled after we experienced intermittent technology issues after a overnight routine maintenance. We sincerely apologize to our customers for any inconvenience and gratitude to our employees who are working diligently to catch up. We will continue to notify customers whose trip with us today may be delayed due to problems now solved.