Before the planes were flown into the World Trade Center and the Pentagon, before anyone even knew they had been hijacked, air traffic controller Lino Martins was already tracking trouble in the skies the morning of Sept. 11.
"He was off-route and not responding," says Martins, one of several dozen air traffic controllers on duty at the FAA's Boston Air Route Traffic Control Center in Nashua, New Hampshire that morning. The "he" was American Airlines Flight 11, a Boeing 767 that had just taken off from Boston's Logan Airport. The flight had gone radio silent and stopped obeying air traffic control instructions and it was now flying into Martins' sector.
"We lost the transponder -- That's when my concern turned to worry," recalls Martins.
A plane's transponder tells air traffic controllers like Martins crucial information such as the flight's altitude and speed. Someone in Flight 11's cockpit had turned it off. But Martins could still see the plane's location on his radar screen so he went to work steering other incoming planes clear of Flight 11's path.
"No ground speed, no altitude readout," recounts Martins. "I was just turning all the airplanes away from him."
Flight 11 was supposed to fly west to Los Angeles, but over Albany, it made a sharp left turn and headed south towards New York City.
"[I] realized this is probably a hijacking," says Martins.
As the 767 continued south out of Martins' sector, he was relieved from his position so he could help with the investigation.
"[I] went down to the cafeteria to get a cup of coffee and I'm watching the TV," Martins recalls. "And I see an airplane hit the tower and right away I knew -- That's American 11... It had to be."
It was 8:46am. American Flight 11 had struck the North Tower of the World Trade Center 47 minutes after it had taken off from Boston and just six minutes after it left Martins' sector.
Less than twenty minutes later, United Flight 175 crashed into the South Tower, then American Flight 77 into the Pentagon, then United Flight 93 into a field in Shanksville, Pennsylvania.
"We just kept hearing one after another and it was just like, 'Oh my God. Make it stop,'" Martins remembers.
At 9:42am, the FAA gave the unprecedented order to close down U.S. airspace.
"We were given instructions," explains Martins. "Everybody lands, no one takes off."
There were nearly 4,000 planes in the air over the U.S. at the time.
"We all buckled down and did our jobs. We just got real busy and did it," says Martins. "Once we got all the airplanes down, that was it. We could sit there and [give a] sigh of relief. It's done."
And done it was. Remarkably, Martins and his fellow air traffic controllers had landed every plane in the nation's airspace in under three hours, without a single accident.
"I did what I could," Martins says. "I'm kind of proud that I did my job ... proud of all my colleagues that we did a good job, did what we could. I don't think there's any more we could have done."
But there was one thing that Martins could never do again.
"I did not work another 9/11 the rest of my FAA career," he says, "That's how I dealt with it."
Martins retired from the FAA in 2009 and now works the tower at Sikorsky Memorial Airport, a small general aviation airport outside of Bridgeport, Connecticut. He will be working this 9/11.