Workers worked day and night to clear the wreckage and recover colleagues killed during the attacks. The site was officially cleared around Memorial Day, 2002, about 4 months earlier than expected.
The last standing piece of building steel, which was part of the South Tower, was draped with an American flag and carried out during a ceremony marking the last day of the recovery work. It was a symbol for all those lost whose bodies were never recovered or identified. It will be used to construct the bow of a new San Antonio-class amphibious assault ship, USS New York (which is explicitly named for the state, not the city).
See World Trade Center site for reconstruction news.