CHICAGO (AP) - Southwest Airlines has cancelled all of its fights in and out of Midway International Airport, its Chicago hub, days after federal authorities closed the airport's control tower after technicians tested positive for the coronavirus. Friday's move by the Dallas-based airline resulted in more than 173 flight cancellations Friday. The Federal Aviation Administration closed Midway's control tower on Tuesday after several technicians tested positive for coronavirus. The FAA said the airport remained open and operations would continue at a reduced rate until controllers and technicians have a safe working environment. As of Thursday, 422 people statewide had tested positive for COVID-19, the disease caused by the virus. Four have died.

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