History: Collapse Of The World Trade Center, September 11, 2001, Lower Manhattan, New York City, United States

On March 13, 2006, workers arrived at the World Trade Center site to remove remaining debris and start surveying work. This marked the official start of construction of the National September 11 Memorial & Museum, though not without controversy and concerns from some family members. In April 2006, the Port Authority and Larry Silverstein reached an agreement in which Silverstein ceded rights to develop the Freedom Tower and Tower Five in exchange for financing with Liberty Bonds for Towers Two, Three, and Four. On April 27, 2006, a ground-breaking ceremony was held for the Freedom Tower.
In May 2006, architects Richard Rogers and Fumihiko Maki were announced as the architects for Towers Three and Four, respectively. The final designs for Towers Two, Three and Four were unveiled on September 7, 2006. Tower Two, or 200 Greenwich Street, will have a roof height of 1,254 feet (382 m) and a 96 feet (29 m) tripod spire for a total of 1,350 feet (410 m). Tower Three, or 175 Greenwich Street will have a roof height of 1,155 feet (352 m) and an antenna height reaching 1,255 feet (383 m). Tower Four, or 150 Greenwich Street, will have an overall height of 946 feet (288 m). On June 22, 2007, the Port Authority of New York and New Jersey announced that JP Morgan Chase will build Tower 5, a 42-story building on Site 5 occupied by the Deutsche Bank Building, and Kohn Pedersen Fox was selected as the architect for the building. Four renowned architects, including Spanish architect Santiago Calatrava, who designed the transit hub, One WTC designer David Childs of Skidmore, Owings and Merrill, and the famed British architect Norman Foster of Foster and Partners designed Tower Two and masterminded the iconic diamond design, will greatly enhance the street-level atmosphere of the rebuilt site. The projects will be complete between early 2013 to mid 2014.
As of August 2011, One World Trade Center is at 80 stories with glass up to the 54th floor, Tower Four is up around 38 stories with glass up to the 15th floor, and the former Deutsche Bank Building has been completely dismantled and the Port Authority is working on their Vehicle Security Center. The World Trade Center Transportation Hub's PATH hall is nearly complete. The memorial officially opened to relatives of the deceased on September 11, 2011, and to the general public on September 12. World Trade Center Tower Three's foundations are becoming visible, and will be completed in mid 2014 if Silverstein Properties can meet requirements set by the Port Authority, as they very likely will. Tower Two will also be completed on schedule according to the construction company. In the December of 2011, Tower Two's foundations are finished and is starting to assemble the frame. Because numerous American and Chinese companies are "very interested" in leasing space at the WTC, Two World Trade Center is likely to be finished earlier than expected. Publishing Giant Conde Nast has agreed to move its headquarters to One World Trade Center, and with this shift, many more are expected to follow.