First three galleries show terrorist attack of September 11, 2001. Many pictures were taken at the entrance to World Trade Center, just minutes before collapsing.

WTC site (part of the financial capitol of the world) was called Ground Zero after the collapse of towers. Ruins of World Trade Center complex in Ground Zero galleries.

First few months after the tragedy. Life and businesses in Ground Zero surrounding area are slowly coming back to normal. Streets of Lower Manhattan in NYC Rising after Attack galleries.

The Tribute in Light marked the six-month anniversary of the terrorist attacks of September 11.

A viewing wall at the Ground Zero edge lets pedestrians to look inside the boundaries of the former World Trade Center.

The gallery shows WTC in period before and during reconstruction.

World Trade Center was a complex with characteristic 110-story twin towers. More than 40,000 people worked here every day.

The gallery shows WTC before September 11, 2001.

On September 11, 2001 at 8:42 A.M. United Airlines Flight 93 took off from Newark International Airport in New Jersey. Hijacked plane did not reach its target crashing in rural southwest Pennsylvania.

The gallery shows Flight 93 crash site and temporary memorial.