NEW YORK - Chris Hardej's eyes well with tears as he recalls the unforgettable day: "I would be the last one to get out alive from my office."

Some survivors like Hardej tirelessly retell the story of the fiery collapse ten years ago of the World Trade Center. Others absolutely refuse to speak of it. And some have radically remade their lives because of it.

In Hardej's case, he goes four times a month to the site of the Twin Towers in lower Manhattan to the Tribute Center, a small museum established by an association of families of victims of the September 11, 2001 attacks.

Along with 400 other volunteers, the New York transportation worker leads visitors on a tour of the site, and recounts his experiences the day Al-Qaeda militants flew hijacked airliners into the Twin Towers.

Happy that the New York landmark is undergoing a rebirth before the 10th anniversary of the attacks, he explains how it once was and what it will look like once the enormous construction project involving hundreds of workers is completed.

And he recalls his escape from his 87th floor office, descending the darkened stairs of the North Tower with two colleagues amid scenes of panic. Firemen passed them in the stairwell, climbing up the burning building, never to be seen again.

Hardej and his co-workers followed voices through the dark until finally exiting the doomed building. He vividly remembers the "eerie calm" after the towers collapsed.

He says that he is a happy man today. "I have not changed much," he said.

"I went to a funeral last night. Somebody I knew, who had breathing problems," he said.

Chris also has had some minor breathing problems, too, a common complaint of 9/11 survivors, but is not concerned. "I am a survivor," he said.

Nearly 3,000 people were killed in the attacks, 2,753 at the World Trade Center and the others in attacks on the Pentagon and in a hijacked plane that crashed in Pennsylvania.

For thousands more, traumatized by the experience, it has taken years to restore meaning to their lives.

John William Codling, 35, has radically changed his life. He used to work for Euro Brokers, on the 84th floor of one of the towers. His goal, he said, was "to make money."

Codling wasn't at work on September 11, but his life came to a halt anyway. He knew about 50 people who lost their lives.

"I was working with them at a bond desk, 10 hours a day. We were very close," he said. "They were really special people, (and) had lots of projects."

Codling left New York and moved in with his parents, suffering a nervous breakdown on the first anniversary of the attacks.

"For two years I was a real zombie," he said. "I couldn't talk about it for a very long time."

Instead, he fantasized about killing Osama bin Laden himself.

He became a painter, and painted pictures of Osama bin Laden dead. He had his first exhibit, and then a second called, "Me I play."

Very slowly, he got his life back. Today, he is the father of a three-year-old boy. He still paints. He has returned to New York, and life is good.

"Ten years is probably the right amount of time to start moving on," he said.