By SCOTT MAYEROWITZ
Traffic at Chicago's two busiest airports was slowly returning to more normal levels Monday, three days after a fire at a regional air traffic control center disrupted much of the nation's air-travel system. The Federal Aviation Administration has temporarily assigned other controllers to oversee the airspace normally covered by the crippled suburban facility, but full service may not be restored for two weeks. A closer look at some key questions surrounding the many delays and cancellations...
