9. An unidentified New York City fireman walks away from Ground Zero after the collapse of the towers. Photographer Anthony Correia told LIFE.com of this picture: "He just looked so exhausted, so beat up." Correia knelt down and took his shot as the man walked by. "I acknowledged him, and he acknowledged me. But he never stopped." The steady gaze, meanwhile, of this lone firefighter allows us a window into the experience of literally thousands of rescue workers and first responders. I was in there, his eyes seem to say. Be thankful that you can't imagine what I saw.
(Photo: Anthony Correia/Getty Images)