I think about photographs as being full, or empty. You picture something in a frame and it's got lots of accounting going on in it-stones and buildings and trees and air - but that's not what fills up a frame. You fill up the frame with feelings, energy, discovery, and risk, and leave room enough for someone else to get in there.

A lot of what I am looking for is a moment of astonishment, he says. Those moments of pure consciousness when you involuntarily inhale and say 'Wow!'

Then I thought, Whoa. If there are no photographs, then there is no history. I'm going to get in there. I'm going to make these pictures. We need a record.

The thought for us [street photographers] was always: How much could we absorb and embrace of a moment of existence that would disappear in an instant? And, Could we really make it live as art? There was an almost moral dimension.

I photographed the entire thing in color because to photograph it in black and white would be to keep it as a tragedy. Because there is a tragic element to photographing, in this case not war, but the collapse. It was just destruction.

We think of photography as pictures. And it is. But I think of photography as ideas. And do the pictures sustain your ideas or are they just good pictures? I want to have an experience in the world that is a deepening experience, that makes me feel alive and awake and conscious.

Making any statement of your feelings is risky. It's just like making pictures.