(CNN) -- A contract employee at a Chicago-area air traffic control center apparently set a fire and tried to kill himself, officials said Friday, shutting the facility and stopping all flights at the world's second-busiest airport.
The bizarre situation has resulted in a "ground stop," triggering the cancellation of more than 700 flights at O'Hare International Airport and more than 150 at nearby Midway Airport, according to the Chicago Department of Aviation.
The employee was being treated after suffering self-inflicted wounds, and police said the incident wasn't related to terrorism. A 50-year-old man at the FAA facility, which controls air traffic for a giant swath of the Midwest, was treated for smoke inhalation, authorities said. Investigators with the FBI and Bureau of Alcohol, Tobacco, Firearms and Explosives were on the scene.
The stoppages have the potential to create a nightmare ripple effect for travelers flying to O'Hare, which serves more than 1,000 flights each day. Last year, it handled 883,000 takeoffs and landings, ranking it as the second-busiest airport on the planet, according to Airports Council International.
The closure affected so many flights because the center controls planes not just flying in and out of Chicago, but also those flying long-distance routes to other regions, raising the potential for thousands of flight delays nationwide.
It lit up social media with complaints by travelers like @JoeMFox who tweeted, "I'm starting to consider whether a five-hour drive would get me there faster than United. #ohare"
In a typical backup plan for a disabled FAA center, the FAA could assign air traffic control authority to FAA centers in other cities, such as Indianapolis, Cleveland, Minneapolis or Kansas City. The O'Hare ground stop has potential repercussions for flights approaching Chicago from across the Atlantic or Pacific. For those airliners, limited fuel would be a concern, as they near the end of their long-distance routes. They could be redirected to other airports.
Union spokesman Doug Church said air traffic controllers are bracing for a tough day. "Indianapolis Center is one of the major facilities bearing the brunt of the extra workload today due to the Chicago Center situation," Church said. "They are doing what they can to support."
Responders at the FAA Center, which is in Aurora, Illinois, found a person suffering from cuts to at least one wrist, two law enforcement officials told CNN, citing initial reports from investigators.
The fire closed the control center around 5:42 a.m.
The airport is a main hub for United Airlines and other major carriers with flights headed to international destinations. When controllers stop flights scheduled to fly to O'Hare, it has the potential to trigger a line of falling air traffic dominoes that will ruin travel plans for countless would-be passengers
Illustrating the point, the flight tracking website FlightRadar24.com showed no aircraft flying in an area stretching from eastern Iowa to central Michigan.
"Anything (that was bound for Chicago) that is still on the ground in its originating city is holding there," American Airlines spokeswoman Leslie Scott said. "Anything in the air has the possibility of being diverted. And anything on the ground in Chicago will stay there."
Workers at the Aurora center were evacuated, FAA spokeswoman Elizabeth Isham Cory said.
Smoke at FAA facility stopped Chicago flights in May
Friday's flight stoppages come four months after smoke at an FAA radar facility in Elgin, Illinois, prompted flight cancellations and delays at O'Hare and Midway.
In that May 13 incident, most flights in and out of O'Hare were delayed by an average of an hour or more, and more than 600 flights were canceled, the Chicago Department of Aviation said. Some 75 flights were canceled at Midway.
The smoke in that May incident was caused by a faulty motor in an air conditioning system, the FAA said at the time.
Pat Rowe from Mitchell International tells FOX6 News that there are currently two flights that have been cancelled. The arrivals/departures are updated regularly on Mitchell International Airport’s website.