"The strobe lights flashed, the speaker gave a little 'woop, woop' and a voice came on the PA system and said, 'Your attention, please, ladies and gentlemen: Building two (the South Tower) is secure. If you're in the midst of evacuation, you may use the reentry doors and the elevators to return to your floor.' ... I came out of my office and came nose-to-nose with a coworker of mine, Bobby Call , and I said, 'Bobby, what have you heard?' He said, 'Well I was down a few floors and I heard the announcement, and I came back up --' and he was in the midst of that sentence when, 'boom, boom,' this loud double explosion again. And it was really, I didn't know it at the time, but it was our building being hit and then the plane exploding inside."

On the way down, he stopped to help another man, Stanley Praimnath, who was trapped in rubble on the 81st floor. The two got out of the building just minutes before it collapsed.

Brian Clark was an executive vice president at Euro Brokers, working on the 84th floor of 2 World Trade Center on Sept. 11, 2001. He was one of the few people who were able to escape from one of the floors above where the plane hit the building.

"...And I had this feeling wash over me: 'Brian, you'll be OK.' And for the rest of the day I felt like I was in control of what I was doing."

On his scariest moment of the day

"Our floor just fell apart. Everything came out of the ceiling — air conditioning ducts and speakers, the works, if you like, fell down. No electricity. The air was filled with white, chalky construction dust. There was no flames, no smoke at that point. And the building swayed — for 10 seconds I was terrified — and fortunately, for me, in hindsight, that was the only moment of the day that I was afraid. ... Whether this really happened or not, I can't say with certainty, but the sensation was ... the building swayed six to eight feet. And then it stopped. And then for five seconds it came back to vertical. ... And I had this feeling wash over me: 'Brian, you'll be OK.' And for the rest of the day I felt like I was in control of what I was doing."

On getting out of the tower

"I had a choice: to turn right to Stairway C, go straight ahead to Stairway B or turn left to Stairway A. I was intending to go to Stairway C, and I felt this almost push on my left shoulder. It was a very strange feeling, but there was nobody there, but it pushed me to the left and I started down Stairway A. I just sort of went with it. And with the six or eight people following me down the stairs in the darkness with my flashlight on, we only went down three floors."

On helping Stanley Praimnath

"I was distracted ... by a stranger's voice inside the 81st floor. I grabbed the shoulder of the fellow beside me, a coworker, Ron DiFrancesco, and I said, 'Ron, we gotta get this guy.' ... Halfway to the stranger, Ron was overcome with the smoke and he went back to the stairs. I continued on to this stranger, kind of dug him out of the rubble and the two of us went back to the stairway. And I guess that was the fateful moment: I shined the light down the stairs. I only saw smoke billowing up, not any flames and we just started down. We dug our way through a lot of rubble, and got out of the building at about four minutes to 10."

On watching the South Tower collapse

"My new best friend Stanley from Fuji Bank turned around and said, 'I think that building's gonna come down.' I said, 'I don't think so. That's a steel structure. That's carpets and furniture and drapery burning.' And I didn't really finish that sentence when 'boom, boom, boom' from the top, this whole building dissolved in eight to 10 seconds."

On his life after 9/11

"Stanley and I are good friends. ... One of us calls the other one every couple months, and we're blood brothers at this point. It's an amazing relationship. We're very good friends, we have that shared experience. ... I have learned, and I tell other people, that there's no point in wasting time trying to answer unanswerable questions. ... Likewise, one cannot predict the future with any certainty. I went to work that day, a normal day, had no idea was was about to happen. So if you don't dwell on unanswerable questions in the past, you don't worry about the future, it pretty well leaves you with the present, and that's where I try to live every day. Every day's a great day. Some are just greater than others."

Guest

Brian Clark, retired executive vice president at Euro Brokers.