RALEIGH, N.C. (WNCN) – Sixteen years ago on Sept. 11, 2001, the world changed. Nearly 3,000 innocent people lost their lives that day. But one man from the Triangle not only made it out alive from the World Trade Center, he helped save someone who couldn’t save herself.

“It sounded like a bomb,” John Cerqueira remembers while sitting in his north Raleigh home. “Just like a big explosion you could hear and feel.”

Fresh out of North Carolina State University, 22-year-old Cerqueira was still getting used to taking a subway train to his sales job at the WTC, when on that day, he thought he heard one tearing through his office.

“You could hear the fuselage moving through the building,” Cerqueira explains. “Almost like a subway train.”

Cerqueira was on the 81st floor in the North Tower, when at 8:46 a.m., American Airlines Flight 11 crashed several floors above him.

“It shook me, the building, tiles were coming up, the walls were caving in,” Cerqueira describes. “There was fire, smoke and the carpet had turned up somehow like the building had twisted.”

No one knew what happened and no one moved, until just after 9 a.m., when unbeknownst to Cerqueira, United Airlines Flight 175 struck the other tower.

“That’s when the message changed from ‘stay here, everyone is fine’ to ‘OK, let’s get out,'” Cerqueira says. “We found an open stairwell, and everyone [went to] leave.”

Cerquiera remembers there wasn’t any panic, until on the 67th floor, when he and his boss Mike Benfante heard voices above them.

“We heard people yelling upstairs on the 68th floor, so we went back upstairs,” Cerqueira says. “We heard people trying to figure out how to get out.”

He and his boss started directing people to the open stairwell, but one group refused.

“They were all huddled around one of their co-workers, who was in a wheelchair, a big heavy motorized wheelchair that would be hard to move certainly down stairs,” Cerquiera remembers.

The woman was 41-year-old Tina Hansen. They asked her if she wanted help, and she said yes.

“We tried to move the wheelchair, and it was way too heavy to move easily and so we picked her up and as we moved toward the door,” Cerqueira says. “One of her co-workers found and brought us an emergency wheelchair.”

That’s when the two men started the long process of moving her down 68 flights of stairs to the ground floor.

By this point, the stairwell was packed, and they could barely move. Despite feeling helpless, Cerqueira says he never felt hopeless.

“The option to focus on helping somebody else was really kind of a relief,” Cerqueira recalls. “It was so tense that there really wasn’t any noticeable panic, praying, it was almost as if it was a collective effort for everyone to stay calm.”

Cerqueira and company had made it 20 floors down when the doors in the stairwell doors blew open from the force of the South Tower collapsing. It was then they met firefighters moving up, and they took a quick break. Cerqueira used an office phone to call his father in North Carolina who was beside his mother, watching it all unfold on live television.

“I told them that I was still in the building, and I was getting out as quickly as I could,” Cerqueira says. His father’s only response: “Get out, hurry up!”

It took about an hour total for them to get out and put Hansen in an ambulance. It was then they realized they had stepped into a nightmare.

“We would hear this very distinct, like a car crash sound,” Cerqueira says, searching for words. “Those car crash sounds, all of them were people falling out of the building.”

It didn’t take long before Cerqueira’s building also fell. Grainy video footage from a news photographer on the ground captures the moment as Cerqueira and Benfante run by, away from the collapse and its billowing smoke and debris.

“It was like a bad dream where you can’t move as fast as you’d like and there’s a monster chasing you,” Cerqueira says. “That’s what it was like.”

For Cerqueira, the bad dream is over, replaced with happy moments, like watching his daughter’s dance recitals or recently seeing her off to kindergarten.

But he continues to look at life through his experience that day 16 years ago.

“If we’re focused on helping other people and suppress our self-centered motives,” Cerqueira explains with a smile, “we’re in a much more powerful position to help, to be productive and be successful.”

Cerqueira now works for ASLAN, a sales training firm. He still keeps up with his old boss, and a year after the terror attack, he was at Benfante’s wedding, alongside Tina Hansen in her new wheelchair.