Southwest Airlines said Monday it would be able to operate “close to normal” at Midway Airport after canceling all flights Sunday, a situation it blamed on an equipment malfunction and a shortage of de-icing fluid. Southwest said it “proactively canceled” about 220 flights and was offering refunds or flight vouchers, WBBM-TV reported. Southwest has "multiple glycol deliveries" scheduled for Monday and expects to resume "close to normal operations" at Midway, she said. Airport (@fly2midway) February 11, 2018 
 
 Due to having to deice many of our aircraft because of the weather, we are running low on deicing fluid.
– Thousands of travelers booked on Southwest Airlines flights out of Chicago's Midway Airport had to change their plans after the airline found out that it didn't have enough de-icing fluid—for the second time this winter. An airline spokesperson said Southwest had "actively worked to manage" its level of glycol, which is used to de-ice aircraft, but "proactively" canceled at least 220 flights Sunday after levels ran low, USA Today reports. Midway Airport said a total of 250 flights were canceled after an icy storm, suggesting other airlines were also affected, though operations are expected to return to normal Monday, the Chicago Tribune reports. Forbes notes that the same thing happened in December, when Southwest canceled at least 90 flights from Midway due to de-icing issues.