An Southwest Airlines Boeing 737-800 Passenger Jet, operating as Southwest Flight WN2504, suffered a near collision today at Midway International Airport in Chicago, Illinois; after a Challenger 350 Business Jet, operating as FlexJet Flight LXJ560, decided to cross the Runway that the 737 was attempting to land on. Thanks to the quick thinking of the Pilots aboard the Southwest Flight, they were able to abort the landing, avoiding a Major Disaster.