I spent a very very long time visiting New York immediately after September 11, 2001. 
I was struck by the faces of all the people who were affected by that tragedy in a way that I was and am completely unable to understand. I sought out their faces in all the photographs I took of the spectacle that is Times Square. They are here, in a book, posted here in pdf format. The file is large. Note that the page numbers are not in sequence because I numbered them for print, not for the purpose of a large PDF file.
From the introduction:
Between October 2001 and March 2005 I made 9 separate trips to New York City to photograph Times Square. At first I concentrated on the buildings and the billboards, but soon began to notice the ubiquitous crowds. Everywhere I turned my camera there were amorphous masses of humanity. Soon I began to photograph the crowds in addition to my photographs of the buildings. I wanted to see who I was missing in my walks through that space. I began to isolate each face from the crowd to make a “portrait”. I wanted to restore the individuality to the people in that massive, chaotic space.
The faces that emerged were haunting and expressive.