(links will open in new windows)
Here is New York has many galleries of photographs of the World Trade Center, 9/11 and the aftermath
Washington Post
Map and diagram of the site with times of the events and photos
Measuring the Rubble
Subterranean Collapse Diagram
CNN page with several 3-D diagrams of the site
Information on the building from where the photographs on this website were taken
Wired New York World Trade Center Map page
Skyscrapers.com World Trade Center page with facts and figures about the buildings
GreatBuildings.com World Trade Center page with facts and figures and many links to photos
The University of Sidney civil engineering department offers an explanation on how the buildings collapsed
Cosmiverse has information on the special techniques used to fight the stubborn underground fires.
SpaceImaging.com Attack on America gallery. Here you can view several very large, very high quality (1-meter resolution) satellite images of Ground Zero in Manhattan as well as the Pentagon.