As vivid as the confusion and fear of Sept. 11 remain for Karen Cooney, she knows it would be worse if she still lived in New York City.
The only way to move forward, she continues to believe, was to move away.
"Every time you would leave the house, there were reminders," said Cooney, who relocated in 2004 to Upper Southampton, Pa., with her husband. "You'd relive that whole day."
While New York has bounced back from Sept. 11 in many ways, with the population growing in the past 10 years even in the area where the World Trade Center collapsed, living there became impossible for some people traumatized by the attack.
There are no good numbers on how many people left the city because of the attacks, but an analysis of census data by the Empire Center for New York State Policy found that 1.6 million New York state residents moved to other states between 2000 and 2010.
Among them were residents who absorbed a huge emotional toll or the resulting economic hit that cost them their jobs.
Cooney lived on Staten Island, home to many firefighters, police officers and others who died that day. Her husband lost a cousin who was in the fire department. Cooney and her daughter even attended funerals for people they didn't know so that the families would see people coming out to support them.
But over time, it just became too much.
"I think if I had not left, I'm not sure I would have handled it as well," she said.
LaShawn Clark vividly remembers the days after attacks: Heightened security in her neighborhood in the Crown Heights section of Brooklyn. Living amid so much tension that the sound of a car backfiring would make people run.
And, worst of all, the constant grief over the loss of Benjamin Clark, her husband and father of her five children, who died in the collapse of the World Trade Center's south tower.
In early 2003, Clark packed up her children and left for Allentown, Pa. She has never regretted it, or the new life she has built, which included getting remarried and giving birth to a sixth child. It's been better for her children, too.
"I've seen them grow and I've seen them heal," she said. "And I've seen them heal much quicker than they would have in New York."
Making such a change gives people who've lived through traumatic events a modicum of control, and that can be positive, said J. William Worden, a clinical psychologist who has written books on grief and grief counseling.
"Anytime you can assert your sense of agency, that's a good thing," he said. "One of the ways you can make meaning is find something positive or redemptive in a situation."
Charles Petersheim did just that. A construction manager, he saw his job disappear when commercial construction dried up after the attack. With his lease expiring, the Lancaster, Pa., native decided it was time to say goodbye to New York.
"Post-9/11, New York was not the most fabulous place to be," he said. "It was very easy to get out of the city and forget about it for a little bit."
He did that by going north to Eldred, N.Y., in Sullivan County, where he had bought a ramshackle property originally intended as a getaway house. He soon saw an opportunity and started a company fixing up homes, then started building old-fashioned houses with modern conveniences.
In the past 10 years, he estimates, he has built 100 homes, selling many to families leaving New York City for a quieter life. He has built his own life in Sullivan County, as well, and now has a wife and small child.
"For me, it was totally the right choice to make," said Petersheim, 41.
Also relocating to Sullivan County was yoga instructor Cheri Brasseale, who lived near lower Manhattan. As a pregnant Brasseale watched the towers burn, she felt her water break _ right on time.
Sept. 11 was her due date.
She made it to her birthing center, where she watching the news on and off as she waited for her child. She gained perspective on the pain of childbirth.
"If people are dying and grieving, then I can birth a child," she said.
Her son Kai was born at 1 a.m. Sept. 12. She left the city for a time a couple of days afterward, heading up to her and her husband's weekend home in Cochecton Center. It's now their permanent home.
Part of the draw of their current home is that it gives her a sense of community, something she said was lost in New York in the years after Sept. 11 because of the country's polarized political climate.
Now, instead of the urban jungle, she spends her days on a 10-acre spread with chickens, sheep and goats, in a place where she knows the people who own the theater and the bakery.
"I'm happy with my choice," she said.
For Clark, the mother of six, part of the tension stemmed from the constant presence of Sept. 11 even afterward _ the news accounts, the day-to-day living in a place where everybody had been affected in ways large and small.
"You've made history and you've haven't even tried to make history," said the 45-year-old chef, who this month moved to Charlotte, N.C. "You never expect death will come in a way that it's continuously repeated."
Some of the effect of the attacks followed Cooney and her family after they left Staten Island. She made sure she familiarized herself with her new home by figuring out ways to get back in case of an emergency, something she wasn't able to do in the panic of Sept. 11, when she couldn't contact her family.
But the years since they moved have been good for them.
"It was a good decision," she said. "It was the healing process, and that's how we coped."