Smoke in a regional radar facility has forced a halt to all incoming and outgoing flights at both of Chicago's airports.
The Federal Aviation Administration says all its personnel were evacuated from the Chicago Terminal Radar Approach Control, or TRACON, facility in suburban Elgin at around 11:30 a.m. central time Tuesday.
Spokesman Tony Molinaro says a ground stop is in effect for all flights in and out of O'Hare International and Midway airports.
Molinaro says inbound flights already in the air over the area were handled by a backup facility in the city of Aurora.
The FAA did not immediately release other details.