CHICAGO » A contract employee set fire at a suburban Chicago air traffic control center where he worked, bringing two of the nation’s busiest airports to a halt Friday, according to a criminal complaint.

Brian Howard, 36, of Naperville, Illinois, is charged with destruction of aircraft or aircraft facilities, a felony. When paramedics found him, the criminal complaint says, he was trying to cut his own throat. The FBI said Howard remains hospitalized and no court date has been scheduled.

Delays and cancellations rippled through the air travel network from coast to coast after the fire. The ground stoppage at O’Hare and Midway airports immediately raised questions about whether the Federal Aviation Administration has adequate backup plans to keep planes moving when a single facility has to shut down.

By Friday night, more than 2,000 flights in and out of Chicago had been canceled. A few flights resumed around midday, after a nearly five-hour gap. The planes were moving at a much-reduced pace, officials said, and no one could be sure when full service would be restored.

The early morning fire forced the evacuation of the control center in Aurora, about 40 miles west of downtown Chicago. It was the second unexpected shutdown of a Chicago-area air traffic facility since May.

Howard worked for the FAA contractor that supplies and maintains communications systems at air traffic facilities, said Jessica Cigich, a spokeswoman for Professional Aviation Safety Specialists, the union that represents FAA technicians. He was recently told he was being transferred to Hawaii, the complaint said.

According to the complaint filed in U.S. District Court in Chicago, a relative who saw a suicidal Facebook note posted on Howard’s account early Friday alerted authorities. Meanwhile, a 911 call from the control center brought a suburban fire department to the scene, where paramedics followed a trail of blood past a gas can, two knives and a lighter, the complaint said.

When they found Howard, he was trying to cut his throat and told the paramedics, "Leave me alone," the complaint said.

Thomas Ahern, a spokesman for the Bureau of Alcohol, Tobacco, Firearms and Explosives, said the man used gasoline as an accelerant.

Howard used a key card to access the center, according to the complaint, and video surveillance shows him dragging a rolling suitcase as he entered. Authorities don’t believe there’s any surveillance video of the crime itself, Ahern said.

When the center was evacuated, management of the region’s airspace was transferred to other facilities, FAA spokeswoman Elizabeth Cory said.

The FAA said in a statement Friday evening that it was managing the Aurora facility’s traffic through centers in Cleveland, Indianapolis, Kansas City and Minneapolis. The agency said it would continue working with those centers over the weekend to reduce disruptions.

The shutdown quickly spread travel misery around the country, with airports as close as Milwaukee and as far as Dallas canceling flights.

Online radar images at one point showed a gaping hole in the nation’s air traffic map over the Upper Midwest. Some passengers already in the air headed for Chicago wound up elsewhere. Southwest Airlines said it scrapped all of its flights at Midway and Milwaukee for the entire day.

"This is a nightmare scenario when we thought systems were in place to prevent it," said aviation analyst Joseph Schwieterman of DePaul University in Chicago. "Technology is advancing so fast that … there’s less of a need for air traffic control to be so geographically oriented. I think the FAA’s going to find itself under a microscope."

The disruption was also likely to deliver a financial hit to airlines, Schwieterman said.

The FAA’s statement did not address the delays, and a spokeswoman in Chicago did not respond to a request for comment about the agency’s backup planning.

Brothers Glenn and Gary Campbell, of suburban Chicago, had planned to travel to the Orlando, Florida, area to attend their father’s 80th birthday party. Instead, they settled for refunds.

"That it is so easy to disrupt the system is disturbing," said Gary Campbell, a carpenter from Crystal Lake, Illinois. "They need to see how to make sure this kind of thing doesn’t happen again."

In May, an electrical problem forced the evacuation of a regional radar facility in suburban Elgin. A bathroom exhaust fan overheated and melted insulation on some wires, sending smoke through the facility’s ventilation system and into the control room. That site was evacuated for three hours, and more than 1,100 flights were canceled.

The Aurora facility, known as an enroute center, handles aircraft flying at high altitudes, including those approaching or leaving Chicago airports. Air traffic closer to the airports is handled by a different facility and by the control towers at the airfields.