The flicker of a single lighter's flame brought our nation's air travel system to its knees.

According to an FBI affidavit, at 5:06 a.m. Friday, airport telecommunications contract employee Brian Howard, 36, used his key card to enter the basement of the radar facility he worked at in Aurora, Illinois — one that's responsible for traffic at O'Hare, one of the nation's busiest airports. He was carrying a black roller bag.

"Take a hard look in the mirror, I have. And this is why I am about to take out ZAU [the three-letter call number for the control center] and my life," read a message posted to Facebook 30 minutes after Howard entered the facility, according to the complaint. "I'm gonna smoke this blunt and move on, take care everyone."

Paramedics responding to a 911 call entered the basement of the Control Center to find smoke above the floor and blood on the ground. The blood led to a spot with a gas can, nozzle, rags that appeared burnt, a black roller board case and a floor panel with exposed telecommunication wires.

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The trail of blood continued to a knife and a lighter, then another knife and then two feet sticking out from under a table. The first responders found Howard, who the affidavit said had recently been told he was being transferred to Hawaii. He had cuts on his arms and was actively slicing his throat with another knife.

The effects of the fire he's charged with setting were immediate.

It damaged the FTI system, the FAA’s telecommunication backbone through which it communicates with all other air traffic facilities. The blaze damaged 20 of the center's 29 racks of computer equipment. Critically, it also damaged the cable connecting the center with the O'Hare control tower. Airlines had to fax in flight plans, and controllers had to manually enter all the information, according to National Air Traffic Controllers Association (NATCA) spokesman Doug Church. A temporary ground stop went into effect for all arrivals and departures at both Chicago's O'Hare and Midway International, grinding all traffic at the airports to a stop.

Duties for directing traffic at O' Hare, a hub for United Airlines and other major carriers, were handed off to four surrounding regional routing centers.

"This is the biggest challenge we have experienced in the national airspace system since the tragedy of 9-11," NATCA president Paul Rinaldi told NBC News. "You have a very large chunk of airspace that is not being controlled by anybody."

The facility's central location and regional importance caused a chain of flight problems. Airlines, already running high passenger loads and tight schedules to maximize profits, struggled to cope, and cancellations quickly mounted.

On Friday, more than 2,000 flights were canceled. That dropped by Sunday, but still more than 700 flights were canceled. On Monday, O'Hare was experiencing delays of 20 minutes or more and more than 300 flights were delayed. Delays at Chicago's Midway airport averaged 45 minutes, with just a few flights canceled.

FAA officials estimate the delays could last up for two weeks until round-the-clock repairs are completed. The agency said Sunday it hoped for repairs to be completed by October 13th.

On Monday, FAA Administrator Michael Huerta announced a review of contingency plans for major failures and outages and a review of security procedures at airport facilities.

The question is, if one individual with a lighter can do this, is the entire air traffic system vulnerable to an inside job?

"The telecommunication system is segregated from the rest of the systems and we're working closely with our contractor to focus on how we can restore the system there," Huerta told NBC News. "All of the facilities have appropriate levels of security and we have actually increased the security at our facilities."