The World Trade Center was destroyed on 09/11/2001 by hijackers who crashed commercial airline flights into the twin towers.  As I write this, it is estimated that 5,000 people lost their lives.

The links below provide a list of the victims in each aircraft or building. The lists were collected from msnbc.com on 9/11/2003. I have provided links the original pages; the contents were copied here in case the links on msnbc.com are ever removed.

Original MSNBC.COM website & pages are provided below (links will open in new window)
American Airlines Flight 11
United Airlines Flight 93

United Airlines Flight 175

World Trade Center
American Airlines Flight 77
The Pentagon

Archived copies of the victims' lists from msnbc.com