Ten years after 9/11, there is nothing unambiguous in the legacy of the attack on the World Trade Center and the Pentagon other than the implacable fact of the dead. This is true, too, for the memorial being unveiled at Ground Zero this weekend, which comes to us as the product of conflicting creative agendas, bureaucratic impasses, and the excruciating logistics of appeasing the families of 2,983 victims (a number that also includes those who died in the financial center's 1993 terrorist bombing). It is remarkable then that the finished site — which will finally cost a total of $700 million, plus an additional $60 million per year to operate — still largely hews to the original vision of Michael Arad, the young architect who rose to national prominence when he won the design competition for the site.

It wasn't easy, to be sure. Only 34 when he watched the second plane hit the twin towers from the roof of his East Village apartment, Arad won the commission (thanks in part to another precocious architect, Maya Lin) to soon find himself in conflict with Daniel Libeskind, the anointed "people's architect" whose master plan for the WTC redevelopment project called for the entire memorial plaza to be sunk into the ground. Arad argued for lifting the plaza to street level, leaving only the footprints of the destroyed towers submerged. He won. He also sparred with relatives of victims over whether his plan was too austere, lacking trees. They won. Then there were his much-publicized differences with Peter Walker, the landscape architect who came on board. "It was a difficult process at times because, especially because as a young designer, I think that you tend to conflate your ideas for the design with one version of its physical manifestation and feel very apprehensive about making any changes to form," Arad says. Now, however, "the process, actually, is part of the design."

An open plaza that somewhat incongruously combines aspects of a public park (grass to sit on, rows of swamp white oaks) with marmoreal cemetery flourishes, the 9/11 memorial today is defined by two sunken black granite waterfalls — the largest man-made falls in America — that are ringed by bronze sheets bearing the names of the dead. "It's a way to communicate and to combat the incomprehensibility of a number close to 3,000," says Arad. "That's a number that I think we all have a hard time relating to, but this makes the losses that were suffered that day... understandable is the wrong word, but you can relate to them," he says. Then, bisecting the plaza, is the above-ground portion of Snohetta's museum commemorating the historical event, which is still being constructed — it is scheduled to open next year — and will stretch beneath the memorial.

To understand how the memorial came into being, ARTINFO spoke to Arad about the genesis of his design and its evolution over the last decade. What follows below are quotes from the architect about his work and some of the debates surrounding the site. The slide show at the left features a detailed, step-by-step account by Arad about the process of conceiving and realizing the memorial.

ON HIS RELATIONSHIP WITH LIBESKIND

"I think that he made a very significant contribution to the design of the site. We haven't walked the site together yet, but we have been meaning to do so. I mean, certainly there were moments that were difficult at the beginning, but I think that eight years later that's behind us. In fact, I met with him recently and now we're actually trying to do something together, somewhere else — a project that will allow us to work together. It's the possibility of a project right now rather than a definite plan. I can't really discuss it. But this is all to say that I understand the challenges that he faces, and certainly we've had difference of opinion, but I respect him as a designer, and think that, at the end of the day, I was able to take the main ideas that he brought to the site and to interpret them, maybe in a slightly different way than he had, but with the same intention of moving the site back into the life of the city."

ON HIS DISAGREEMENTS WITH PETER WALKER

"There are bound to be differences in any artistic collaboration with landscape elements, or theater, of lighting elements. When I approached Peter I brought that idea to the table and Peter helped to implement and interpret it. You know, there's always a sense of collaboration, but not all collaborations can be a walk in the park — it can be challenging. It doesn't have to be a marriage, but even then there are disagreements. I'm very happy with the result. You'll have to ask Peter for his opinion. I was in accord with a number of designers and consultants who played a very important part in contributing to this process. You know, design is a process of rebirth. And if you agree on all the answers, then where is the rebirth?"

ON THE INFLUENCE OF MAYA LIN'S VIETNAM MEMORIAL ON HIS DESIGN

"I think she's a great designer, but I don't think I was trying to emulate a shape or language that was hers. It was a fairly straightforward process for me, of taking a design and this idea of the voids and then trying to understand it. Is there an affinity? I'm sure there are plenty of affinities in the eye of the beholder."

ON THE IMPACT OF MINIMALISM ON HIS DESIGN

"You can see that kind of minimalism in place at Chichen Itza. I really appreciate artists of the 20th century, and I can see a lot of their influence on my work, but to suggest that my design only fits within an 'ism' kind of bothers me."

ON THE RISK OF VISITORS VAULTING THE LOW GUARD SURROUNDING THE WATERFALLS

"I believe that people are fundamentally are decent. And, yes, you will have people that sometimes will misbehave. But 99.9 percent of people out there are not going to behave in that way, and I trust that."

ON WHAT HE'S DOING NEXT

"I'm working on a variety of projects, some very large in scale, some small-scale, some pro bono, some not. I'm doing a green roof in the East Village — a farmable roof for a school building — and I'm also doing a 60-story mixed-use commercial tower in China. They're opposite ends of the spectrum and of the world, but I think both of these projects and all of the projects that our office is engaged in and that my partners are working on are about city-making. As architects we are often involved in the concrete-steel-and-glass aspect of it, but cities are social structures, and to be involved in imagining the future of cities and the type of relationships and the types of places that we're making is something that intrigues me very much. I was able to develop that in the design of the memorial, and I hope to bring that to all of my projects."