Ten years after the terrorist attacks on September 11, 2001, construction continues at the site where more than 2,600 people lost their lives in the worst strike on American soil in the nations history. In November 2001, as Americans across the country continued to mourn the many lives lost, then New York Governor George Pataki began the process of renewal with the establishment of a board to oversee the reconstruction of buildings lost at the World Trade Center site in Manhattan. Chief among them was 1 World Trade Center, formerly dubbed the Freedom Tower. Though several were initially considered, the final design for the Freedom Tower calls for the structure to reach 1,776 feet into the air. It will offer 2.6 million square feet of space for offices, restaurants and other venues. The exterior design of the building incorporates a glass panel facade with tapered corners. Construction began on the tower in April 2006, with the Port Authority of New York and New Jersey taking over development of the project in the fall of that year. By December 2006, the first concrete was poured to prepare the foundation on a project that is expected to come with a final price tag of $3.1 billion. A completion date for the tower is currently expected in late 2013, and by the beginning of August 2011, the building stood nearly 80 stories tall. According to the New York Times, construction is progressing at about one floor per week. The building itself will include environmentally friendly technologies such as renewable energy and a water recycling system, but there will also be several safety features incorporated based on information gleaned a decade ago. When two Boeing 767 jetliners crashed into the north and south towers of the World Trade Center on 9/11, it took less than two hours for the buildings to collapse. A fire in both buildings, resulting from the impact of the airplanes, is believed to have caused the interior structures of the towers to weaken considerably. The new tower will include fireproofing materials in its construction as well as structural redundancy to add extra elements of support. There will also be fireproof elevators, biological and chemical filters in the air supply system, and triple-wide stairways. A greater emphasis was also placed on the facilitation of emergency response. The interior architecture of 1 World Trade Center will include enhanced emergency communication cables and a dedicated stairway for firefighters. These safety measures can be used in conjunction with enhanced elevators, housed in a protected central building core, which will serve every floor of the building, according to information from Silverstein Properties, the towers original developer. At present, four other buildings are planned at the World Trace Center site, while a fifth tower, 7 World Trade Center, became the first to open to the public at the site where the original structures were destroyed on September 11.