9/11 Memorial and the Rebuilding of Ground Zero

For nearly a year after the terrorist attacks of 9/11, workers continued to remove debris and recover bodies from the ruins of the Twin Towers at Lower Manhattan's former World Trade Center complex. Meanwhile, intense debate raged over how best to rebuild the World Trade Center, as well as how to memorialize the thousands of victims. Though initial plans called for the rebuild and memorial to be completed by September 2011--the 10th anniversary of the attacks--a combination of political struggles, financial problems and legal squabbles among the various parties involved led to repeated delays, and rebuild efforts are still ongoing.

Challenges of Rebuilding After 9/11
Immediately after 9/11, a number of prominent leaders--including New York City Mayor Rudolph W. Giuliani and U.S. President George W. Bush--pledged to quickly rebuild the World Trade Center site as an inspiring symbol of American resilience and triumph over terrorism. Among the parties directly involved in the enormously complex project were the Port Authority of New York and New Jersey; real estate developer Larry Silverstein, who leased the World Trade Center from the Port Authority in July 2001; and the Lower Manhattan Development Corporation (LMDC), an organization established in November 2001 to manage federal aid and oversee the rebuilding efforts. As the rebuild got underway, it eventually came to involve (by some estimates) more than a dozen government agencies and some 100 construction companies and subcontractors.

Cleanup and recovery at Ground Zero, as the World Trade Center site became known after 9/11, continued every day around the clock for the better part of a year; an official ceremony in May 2002 marked the end of those efforts. After the LMDC invited a number of top architects to submit designs for the rebuilding of the site, the architect Daniel Libeskind was chosen as the winner. The centerpiece of Libeskind's master plan, known as "Memory Foundations," was the construction of a new tower at 1 World Trade Center that would reach the staggering—and symbolic—height of 1,776 feet (541 meters) including the spire at the top. As the tallest of four new office towers at the site, the "Freedom Tower" (in the words of New York's Governor George Pataki) would represent New York's (and the country's) triumph over terrorism.

Memorial to the 9/11 Victims
A second international competition in 2003 asked for design proposals for a national memorial to honor and remember the men, women and children killed in the terrorist attacks of 9/11 as well as the bombing of the World Trade Center on February 26, 1993. The winning design--"Reflecting Absence," by Michael Arad and Peter Walker--was chosen out of more than 5,000 submissions from 62 countries in early 2004. After construction of the memorial began in 2006, ballooning costs led developers to scale back plans in order to cut the budget from $1 billion back to the original $500 million.

The National September 11 Memorial and Museum occupies about half of the 16-acre World Trade Center site. It contains two large waterfalls and reflecting pools, each about an acre in size, set within the footprints of the Twin Towers that fell on 9/11. On the bronze parapets surrounding the pools are inscribed the names of the nearly 3,000 people killed in the terrorist attacks of 9/11 as well as those killed in the 1993 World Trade Center bombing. The memorial is scheduled to be dedicated on September 11, 2011, in a ceremony for the families of the victims; it will open to the public the following day. The museum is scheduled for an opening date of September 2012.

The Freedom Tower and Other WTC Site Buildings
After multiple changes to Libeskind's original design of the Freedom Tower and prolonged disputes between the various parties involved over financing, Silverstein handed control over the building's development to the Port Authority in 2006, and construction of the tower began in earnest after that date. In 2009, the Freedom Tower was officially renamed 1 World Trade Center, perhaps in response to concerns that the original name would make too tempting a target for future terrorist attacks. After years of sluggish progress, the rebuild effort quickened significantly in 2010, with 1 World Trade Center reaching the halfway point of its final height (693 feet above street level) by December. The tower is expected to be completed in 2013.

As for the rest of the complex, a new tower at 7 World Trade Center, rebuilt on the site of a 47-story building that was the last to collapse on 9/11, opened in 2006. The $2 billion 4 World Trade Center, located at the southeast corner of the site, will house more than 50 floors of office space and five stories of retail space; it is scheduled to be completed in late 2013. An ambitious glass and steel transit concourse, designed by the Spanish architect Santiago Calatrava and expected to cost nearly $3.5billion, is scheduled for completion in late 2014, while Silverstein's 2 and 3 World Trade Center will be completed sometime after 2015.
[Source: http://www.history.com/topics/9-11-memorial]