The Federal Aviation Administration is reviewing security practices and how it deals with unexpected incidents throughout its air traffic control facilities following last week's fire at a Chicago-area air traffic facility, agency administrator Michael Huerta said Monday.

The fire brought flights at the city's two busy airports to a halt and disrupted air service across the country. Authorities say it was set by a contract employee who also tried to commit suicide.

By shifting controllers from the damaged facility to other air traffic centers and expanding operations at other Chicago-area control facilities, the FAA has been able to bring service at O'Hare International Airport back to 60 percent of normal and Midway International Airport to 75 percent of normal, Huerta said.

The team of FAA employees and labor union representatives conducting the review has been asked to "think as creatively as possible" and to complete their work within 30 days, he said.

"If we need to make changes because of the incident that happened in Chicago on Friday I will not hesitate to do so," Huerta told an Air Traffic Control Association conference.

The employee who set the fire worked for the Harris Corporation, which provides the FAA's communications network for its air traffic centers, he said. The room where the fire took place contained communications equipment. Of 29 racks of communications boxes and wiring, 20 will have to be replaced, he said.

The FAA has heightened security at all its air traffic facilities in response to the incident, but the review will look at what more can be done on background checks and access, Huerta said. "Everything needs to be on the table," he said.