The two planes that tore through a brilliant sky on Sept. 11, 2001, instantly threw the life of every New Yorker into upheaval. A decade later, daily routines have resumed, but almost everyone acknowledges the lingering aftereffects -- sometimes subtle, other times remarkably sharp -- in a city whose vulnerability was suddenly exposed.

The Wall Street Journal asked four influential New Yorkers to reflect on how the city has changed in the decade since Sept. 11.

Each of them recalled a different experience in the months after the attacks, but all spoke of their deep commitment to the city they call home.

Geoffrey Canada, president of the Harlem Children's Zone

Geoffrey Canada: I'm on the board of the Robin Hood Foundation, and our office was a few blocks below Ground Zero, and we had a meeting there a few days afterward. We could see the smoking pile, but more importantly we could smell it. And I remember watching the firemen and policemen on the pile and thinking to myself, 'Gosh I hope those guys don't get sick.' I think one of the lastingimpacts of this for me is watching how these guys who were our heroes are seemingly begging for medical support.

A: I don't think many other communities experienced what we experienced in Harlem. We began to have African-American kids beating up Muslim kids, and it shocked all of us. African-American kids thought they were committing some act of patriotism. We began to reach out to the community of those from Northern Africa who live around 125th Street who are mostly Muslim, and create relationships so those folks weren't looking at each other through the prism of stereotypes and wouldn't automatically assume this was a bad person. And that work has continued as these young people have been growing up, [to offset] these sort of messages that they receive via the media, where they're constantly" target="_blank" title="ad.经常地；不断地">constantly being bombarded with terrorism being connected to Islam. We, as a community, live side by side.

A: My organization is going to be supporting a number of activities with young people that will honor 9/11 with volunteering and other work.

I will probably spend the day with my kids. It's a day that always reminds me of how precious family is.

Jennifer Egan, novelist, winner of the 2011 Pulitzer Prize for fiction

Jennifer Egan: I think there was definitely both an immediate and a lasting effect. I remember just being amazed by how surreal and extreme all of it was. For me, the moment that really stands out is hitting those barricades along Canal Street. It looked like a war zone, and that's not something we're used to encountering on American soil. It looked like New York, but it was completely different. There was a huge conceptual shift that occurred for me, which is that we can have these experiences, this catastrophic violence, right here in New York.

It made me feel my love for the city and my willingness to live in these circumstances to enjoy the benefits of being here. I felt like, you know what? If having this kind of diversity and range and sort of amazingcombination of attributes means I have to live a riskier life, I'll do it. It means that much to me. It made me feel a profound commitment to the city, almost a political commitment.

A: It made me even more aware of what a luxury it is. It's akin to not being able to realize the value of childhood when you're a child.

In a way, I'm amazed to think of how safe I feel here again. I think that's freedom -- a sense of unreflexive safety. Having felt that danger and having felt it subside over time has made me feel how viscerally what a luxury it is to feel safe.

A: I don't know. That's a good question. For me it feels like such an everydayreflection. Every single day, I ride over the Manhattan Bridge on the subway, I look at Lower Manhattan and I think, I can't believe those buildings aren't there. I don't need an anniversary to remember.

It's like having a person you love die. The perception of absence and loss is such an everyday thing.

A: There's a whole generation of people in New York that never saw the towers. It's just a myth to them that they were here. And one of the great things about New York is that there's an ebb and flow of people, there's a constant flux. There's never going to be a solid, collective memory of New York. So is there that same camaraderie? No, because it's the nature of the city that there's an openness to it, that we don't all share the same sense.

Donna Lieberman, executivedirector of the New York Civil Liberties Union

Donna Lieberman: I think that the fear and pain that gripped all of us in the aftermath of the attacks made us understand that we were dealing with a new era in terms of freedom moving forward. And I think none of us understood what that would mean, and what we have learned is that a lot of rights that we took for granted turned out not to be written in stone and were indeed compromised, not out of need, but out of fear both of attack but also fear of standing up for principles.

The Constitution stays the same, the rights are still there, but the willingness of our courts and other branches to stick up for those freedoms was in jeopardy.