Instead, the exhibition includes a single work made in direct response to 9/11 -- by Ellsworth Kelly -- and another 70 works by 41 artists largely made prior to the event, by artists including Diane Arbus, John Chamberlain, Christo, Felix Gonzalez-Torres, Thomas Hirschhorn, Barbara Kruger, Yoko Onoand John Lennon, Rosemarie Trockel and James Turrell.