Midway is the airline's largest hub.
No one was seriously injured in that incident on Flight 812 Friday night, which led to the grounding of 170 planes and more than 600 cancelations nationwide over the weekend.
At issue- subsurface cracks that led to the 5-foot-long hole in the passenger cabin roof of Friday's flight. The airline found similar cracks on three other planes.
Planes that passed the inspection are back in service.
As of Monday, only 70 Southwest flights were canceled, and only eight of those cancelations, all of which were morning flights, were flying into or out of Chicago's South Side airport. By Monday afternoon, things were back in business at Midway.
But playing catchup on the canceled flights is going to take awhile. A high school choir from New Mexico was supposed be back in Albuquerque Sunday. Instead, the group of 84 students and 9 adults spent Monday at Millennium Park. And the director is worried they might have to sing for their supper.
"The delay is costing us about $15,000 and so we're trying to figure out how to pay for that," Todd Krier, choir director.
The group could not get a flight out until Tuesday. Students had mixed reactions to the change in plans.
"More school we're missing, testing, stuff like that," Tyler Crawley, student, said.
"Chicago is not a boring city. I'm sure there's something to do," Allison Dunn, student, said.
Those whose flights are taking off also have mixed reviews to flying right now.
"My hands are sweating. I'm scared to death. I have my prayer book in my purse," Barbara Dembs said.
"Slightly nervous, you look up to see if you can see a little crack, but other than that, I was fine," Don Davenport said.
"If you're a frequent flier like I am on Southwest, I would definitely put new planes into the system," John Milstein said.
"Very safe safety record overall. It is just an anomaly at best and doesn't concern me," Paul Furman, Southwest passenger.