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

• History
The process of cleanup and recovery continued 24 hours a day over a period of eight months. Debris was transported from the World Trade Center site to Fresh Kills on Staten Island, where it was further sifted. On May 30, 2002, a ceremony was held to officially mark the end of the cleanup efforts. In 2002, ground was broken on construction of a new 7WTC building located just to the north of the main World Trade Center site. Since it was not part of the site master plan, Larry Silverstein was able to proceed without delay on the rebuilding of 7 World Trade Center, which was completed and officially opened in May 2006; this had been considered a priority since restoring the Consolidated Edison Cos. electrical substation in the building's lower floors was necessary to meet power demands of Lower Manhattan. While 7 World Trade Center was not part of the master plan for the Twin Towers site, Silverstein and Con Edison recognized that the rebuilding of 7 World Trade Center would have to be consistent with the master plan which was expected to re-open the street grid which had been blocked by the original World Trade Center super-block. As a result, the design for the new 7 World Trade Center allowed for the re-opening of Greenwich Street, which had been blocked by the original 7 World Trade Center. A temporary PATH station at the World Trade Center opened in November 2003; it will be replaced by a permanent station designed by Santiago Calatrava.
With the main World Trade Center site, numerous stakeholders were involved including Silverstein and the Port Authority, which in turn meant the Governor of New York State, George Pataki, had some authority. In addition, the victims' families, people in the surrounding neighborhoods, Mayor Michael Bloomberg, and others wanted input. Governor Pataki established the Lower Manhattan Development Corporation (LMDC) in November 2001 as an official commission to oversee the rebuilding process. The LMDC held a competition to solicit possible designs for the site. The Memory Foundations design by Daniel Libeskind was chosen as the master plan for the World Trade Center site. The plan included the 1,776 feet (541 m) Freedom Tower (now known as One World Trade Center) as well as a memorial and a number of other office towers. Out of the World Trade Center Site Memorial Competition, a design by Michael Arad and Peter Walker titled Reflecting Absence was selected in January 2004.
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.