CHICAGO -- More than 1,600 flights were grounded nationwide Friday following a fire at an Illinois air traffic control facility.
The disruption at the Federal Aviation Administration radar facility hit Chicago's busy O'Hare and Midway airports the hardest, grounding virtually all flights at those airports for several hours.
As of 12:25 p.m. ET, more than 1,000 flights had been canceled at O'Hare
Federal and local authorities believe the fire was intentionally started by a contract employee, said city of Aurora spokesman Dan Ferrelli.
The man suspected of starting the fire was found in the basement suffering non-gunshot self-inflicted wounds.
The incident is being investigated jointly by the FAA, ATF, FBI and local authorities. Ferrelli said he did not know if a motive had been established but authorities did not believe it was an incident of terrorism.
Air traffic controllers at the affected facility handle flights that fly across Illinois, Indiana, Iowa, Michigan and Wisconsin. The Associated Press explains that "the Aurora facility is known as an en-route center, and handles aircraft flying at high altitudes, including those on approach or leaving Chicago's airports. Air traffic closer to the airports is handled by a different facility and by the control towers located at the airfields."