Southwest cancels flights over shortage of de-icing fluid

Southwest Airlines canceled hundreds of flights at Midway International Airport on Sunday because of a shortage of fluid used to de-ice planes.

Citing severe winter weather, the airline halted services in Chicago and "proactively" canceled about 220 flights after realizing it wouldn't have enough anti-icing fluid to safely operate the rest of the day, according to a statement from Southwest.

"We will continue to work with our customers on their travel plans and apologize for any inconvenience the disruption in service has caused," airline officials said.

Greg Cunningham, spokesman for the Chicago Department of Aviation, confirmed Sunday that "winter operational issues" caused more than 250 cancellations at Midway. The runways are clear and open, he said, noting the problem is not related to the airport.

Southwest officials said operations are expected to return to normal Monday, when multiple shipments of the de-icing fluid are scheduled to be delivered. The airline will continue to monitor the winter weather moving through Chicago.