The ceramic tiles on the chain-link fence at Greenwich Ave. and Seventh Ave. South are the last spontaneous 9/11 memorial left in the city. They were painted by children at “Our Name Is Mud,” the former ceramic studio next to the triangular lot, which is owned by the Metropolitan Transportation Authority. The M.T.A., which plans to build a fan plant at the site, has said it will work some of the tiles into the project. The spot is just south of the former St. Vincent’s Hospital, which had its own memorial of 9/11 missing-persons posters. Lorrie Veasey, who owned “Our Name is Mud,” told the newspaper in July 2009, “The very purpose of allowing a spontaneous memorial to continue after the event it commemorates is to have a visual record moving away from the event itself. Every faded and yellowed tile, every crack and crumble, to me represents the natural progression of memory from the events of that day.” Not all the tiles feature images of the World Trade Center; some have written messages, others symbols of peace.