On conceiving of the idea:

Michael Arad: My own experience was how important a public space was for New York to come together and respond as a community to what they had witnessed. I had been living here for a few years and I still felt a little bit like an outsider. You couldn’t be alone at the moment, you were really a part of a greater community. And for me, that came from going to places like Union Square and Washington Square and being with other people; it wasn’t a ceremony or a speech or anything it was just being in a public space together. When I saw this, I felt like this was actually cutting this space off from the life of the city and that everything should actually be raised up and connected to the street level. Public space is very resilient in a way, you could have mourning, life and death both being celebrated at the same time in the same place.

I was imagining a sort of urban plaza sort of bound by West, by Greenwich, by Liberty and Fulton and then that big flat urban plaza punctuated by these two voids, two reflecting pools where the footprints of the towers were. So that’s the competition entry that I sent in back in June of 2003, and actually, the last word on this was, the last phrase was work or play. That really stressed that it was important to think of this not just as a point of memory but as a living part of the city that would connect this back into the life of lower Manhattan, otherwise you would be forever cutting it off, I think. So, there would be the big flat plaza at grade and then the memorial galleries behind those waterfalls, sort of a cloister-like space where you would encounter the names.

I was one of eight finalists that were selected by the jury that LMDC assembled, came to see the site at the time, and was given about a month and a budget to take that one board to develop it into more materials, more boards, animation, rendering, a model and present it to the jury and respond to questions that they had. And you can imagine LMDC had a lot of questions because we deviated very much from the guidelines. But I think in some ways that was the jury was looking for. They were challenging the LMDC, they were challenging the master planners, and for me it was about the sort of arrival on this plaza, this processional experience of this descent into darkness and then coming up to the edge of the pools, up to the light, and encountering the names there. The moment of encountering the names, for me was always the emotional heart of this journey, this confrontation with death and the arrival of this threshold that you can’t go past. There’s this enormous, acre-sized pool beyond us of empty space that you couldn’t enter, that you could only stand on the edge of. And then coming back up to the plaza, back to the trees, back to life so to speak.

I showed this model and this rendering to the jury and they said, "You know, this plaza still looks very austere and bleak if it’s only dedicated to memorial uses," and challenged me to come up with another way of looking at the landscape that would bring work and life and play back to the site—but in a way didn’t destabilize this very basic premise of this flat plane with its function of these two voids.

Eventually I came up with this idea of abacus-like bands. It's a series of paving bands which run from one side to the next, unifying the plaza. Along the bands, sort of like beads on the wires of an abacus, trees can be placed at random intervals. And when we you look in a certain direction it looks like staggered and random...but then as you turn or shift your gaze 90 degrees, all of a sudden you see them sort of line up into all of these arrays. Over time I think these branches will form a canopy—almost like naves in a church. So we went back to the jury with that. It was actually almost like a pocket-park in the middle of New York City, and you really had to understand it, eight acres next to the skyscrapers is a very small space and this space is going to be defined so clearly by the buildings around it. They are the walls to this urban room.

The design was selected and we went into production...what began as a solitary activity...now involved everyone in the world.

Dwell: When was that?

It was likely in January 2004. (And, wow that’s coming up on that soon, its own 10th anniversary.) So, one of the first things we had to deal with were the waterfalls and whether we would have water clinging...or would it be more like this waterfall at the World Financial Center, where the water sort of free flows over. And we tested it in Canada in winter and summer, we built full-scale mockups, tried different profiles. And every aspect of the memorial in some way went through these intense process of analysis and discovery...And I think the process to me was very important because you begin with a clear idea but then how it actually is manifested can change, it can take different paths.

We ended up with something where you see each stream of water very clearly as it goes over the wire and the geometry of these metal wire fingers kind of separates the water out and as it falls down the 30 feet, the first few feet you can see each almost as an individual line but then by the time it falls down it’s sort of a woven tapestry of water. It becomes something where those individual lines disappear and it's this notion of where individual loss and collective loss [finds] a way of expressing itself through...the design.

Also...once you have a memorial, it begins to have its own voice; you sort of just have to find the dialogue that expresses that voice. So here was a mockup that we had built in the backyard of our fountain designer up in Toronto. And here you can see the names, you can see the waterfall and the pool beyond. And that was the experience that I imagined would occur in these galleries. It could be a secular but very spiritual space for contemplation. And for a variety of reasons having to do with security and budgetary concerns and the unease that some family members felt about going below the plaza, in 2006 these memorial galleries were eliminated from the design and we were asked to bring these names up to plaza-level. That was the very clear, difficult moment for me. ...

Physically, it had to be different but in every other aspect of the design it should keep its character. And over the next couple of years we explored dozens of different options. It was a very sort of trying period, there was a lot of pressure from a lot of different parties to resolve this issue quickly but a lot of different voices expressing dissatisfaction with one idea or another. One idea that I really liked that didn’t come to fruition was to sort of end the plaza and begin this water table that then would cascade down and breaking the surface of that water table or water floor that was level with the plaza so to speak would be the name of the victims, forming this ring around our falls. And it really unified all of the elements of our design. This idea of the open plaza, the idea of the void, the names, the waterfall, in one gesture. And when that idea was rejected we had another idea that developed which was this sort of sculptural bronze vessel that rang in the void and water came out of the top of it forming sort of rivulets along the front, running across the names, and then across the back that waterfall into the void. And that idea seemed almost too sculpturally aggressive, and you can imagine how difficult it is to design in that.

Dwell: Were you heartbroken when you took the galleries out?

Oh yeah. Devastating.

Dwell: The version when the names are rising up out of the water, which is really beautiful, was that budget?

No, you know that was a number of differences. Some people thought it looked like the names were drowning, others thought it would be hard to touch the names on the floor.

Kelsey Keith: Cause on memorials people are always looking for a specific name.

Yeah, that wasn’t even finding the name, it was just touching it. If you’re in a wheelchair…there were a lot of accessibility concerns. And I think that these designs, which we studied over time, of course, influenced what came out at the end of the day which you’ll see shortly, but which is an 8 foot wide, 2 foot tall water table. And then sort of floating above it is this bronze wing-like shape that the names are incised into. The names are really about the material that’s been removed. So it’s shadows during the day and at night that panel is illuminated from within and these names appear as light. And you should come back and see the memorial at night, it’s completely different.

...

The one thing I didn’t touch on earlier was how the names are arranged, and I just wanted to talk about that for one moment, I know you read a little bit about it. The names are arranged according to a system of meaningful adjacency. We asked for families to participate in this, and they sent us requests for what names they wanted next to the name of the person that they lost. It was kind of a logistical nightmare that I proposed that we engage in but it was really an important thing to do and it really embedded a lot of significant meaning in the arrangement of the names on the memorial. It’s not in alphabetical list, it’s a list that gives each person a physical place on the memorial that belongs to him or her. And the names around the person, siblings or parents or a friend, somebody they went to school with. It really instills deep personal meaning in the arrangement and I think there’s a way to share those meanings to the visitors of the memorial. There’s already an app that people who come here can use to find the name.

Dwell: What’s the app?

Go to the 9/11 memorial website and you can find that; it’s sort of a name-finder thing, but it’s been linked to recorded oral histories that StoryCorp has already been collecting. So for example, if you go to one of the panels here on the South Pole you can hear the father of a man who lost both his sons; one was a firefighter, one a police officer, talk about what they were like when they were little kids. And being able to put their names side by side was very important to us. So there are a handful of stories that have already been recorded and connected to that. ...We got over 1200 requests, which really influenced, at the end of the day, every name here. And we have over 3000 names.