Cities are the greatest creations of humanity.

I studied architecture in New York. So, really I was very moved, like everyone else, to try to contribute something that has that resonance and profundity of it means to all of us.

Well, I think one doesn't really have to invent this memorial space, because it is already there. And it is speaking with a voice and, you know, 4 million of us came to see the site.

In a strange way, architecture is really an unfinished thing, because even though the building is finished, it takes on a new life. It becomes part of a new dynamic: how people will occupy it, use it, think about it.

It's about how to bring together the seemingly contradictory aspects of the memorial, which is about a tragedy and how it changed the world, but also about creating a vital and beautiful city of the 21st century.

I think there is a new awareness in this 21st century that design is as important to where and how we live as it is for museums, concert halls and civic buildings.

When you're a kid with artistic yearnings brought up in the Bronx, you don't get fed up too easily.