"I wanted to do it in front of the Dome in Cologne, but the City prevented it. But there was this little strip of land which belonged to the railways, and a guy who worked there said, 'go ahead'. I didn't want to use these historic photographs which are used too often - those mountains of corpses mean nothing anymore - so I used four metre high children's faces. I photographed children from the area, foreign children, German children, Jews, anything." Mounted in a long billboard line, after the huge word "Selection", the children's faces were powdered in a deathly, bruised way, many with their eyes closed. That may sound subtle, but in the context of muted German Holocaust memorials, it was like a slap in the face. Despite CCTV video-cameras, someone painstakingly sliced the throats of every single child-portrait.