World Trade Center

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This article is about the former twin towers in New York City. For other uses, see World Trade Center (disambiguation).

Coordinates: 40°42′42″N, 74°00′45″W

1 World Trade Center redirects here. For World Trade Center, second version, Tower 1, see Freedom Tower.
2 World Trade Center redirects here. For World Trade Center, second version, Tower 2, see 200 Greenwich Street.
World Trade Center

World Trade Center was the world's tallest building from 1972 to 1973.*

Preceded by Empire State Building
Surpassed by Sears Tower
Information
Location New York City, New York, USA (Lower Manhattan)
Status Destroyed
Constructed 1966-1973
Destroyed September 11, 2001
Height
Antenna/Spire 1,731.9 ft (527.9 m)
Roof 1,368 ft (417.0 m)
Top floor 1,348 ft (411.0 m)
Technical Details
Floor count 110
Floor area 8.6 million sq ft
800,000 m² (1 & 2)
Elevator count 198 (1 & 2)
Companies
Architect Minoru Yamasaki
* Fully habitable, self-supported, from main entrance to rooftop; see world's tallest structures for other listings.

The World Trade Center in New York City (sometimes informally referred to as the WTC or the Twin Towers) was a complex of seven buildings, mostly designed by Japanese-American architect Minoru Yamasaki and developed by the Port Authority of New York and New Jersey. It was initiated in 1960 by a Lower Manhattan Association created and chaired by David Rockefeller, who had the original idea of building the Center, with strong backing from the then New York governor, his brother, Nelson Rockefeller.[1] Larry Silverstein held the most recent lease to the complex, the Port Authority having leased it to him in July of 2001.[2] The complex, located in the heart of New York City's downtown financial district, contained 13.4 million square feet (1.24 million m²) of office space, almost four percent of Manhattan's entire office inventory.[3]

Best known for its iconic 110-story Twin Towers, the World Trade Center was beset by a fire on February 13, 1975 and a bombing on February 26, 1993. All of the original buildings in the complex were destroyed in the September 11, 2001, attacks: 1 WTC, 2 WTC (North and South Towers) and 7 WTC collapsed; 3 WTC (Marriott Hotel) was crushed by the collapses of 1 WTC and 2 WTC; and 4 WTC, 5 WTC, and 6 WTC were damaged beyond repair and later demolished. In addition, St. Nicholas Greek Orthodox Church (not part of the complex) was destroyed by the collapse of 2 WTC.

Contents

[edit] Overview

Bottom view of the World Trade Center.
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Bottom view of the World Trade Center.
View from the World Trade Center.
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View from the World Trade Center.

The idea of a World Trade Center complex originated with Nelson and David Rockefeller in the 1950s as an attempt to revitalize lower Manhattan. The initial proposed site on the East River was later moved to the lower west side. The complex towers were designed by Japanese American architect Minoru Yamasaki with Antonio Brittiochi in one of the most striking American implementations of the architectural ethic of Le Corbusier, as well as the seminal expression of Yamasaki's gothic modernist tendencies.

In 1966, construction of the World Trade Center began with groundbreaking that razed 13 square blocks of low rise buildings, some of which pre-dated the US Civil War. The construction was under the auspices of the semi-autonomous Port Authority of New York and New Jersey. In 1970, construction was completed on One World Trade Center, with its first tenants moving into the building in December, 1970. Tenants first moved into Two World Trade Center in January 1972.[4] The ribbon-cutting ceremony was on April 4, 1973.[5] Ultimately the complex came to consist of seven buildings, but its most notable features were the main twin towers. On any given day, some 50,000 people worked in the towers with another 200,000 passing through as visitors. The complex was so large that it had its own ZIP Code: 10048.

Although the towers became an undeniable icon of New York City, they were not without flaws and were handicapped in many ways. Initially conceived, (as the name suggests) as a complex dedicated to companies and organizations directly taking part in "World Trade," they at first failed to attract the expected clientele; during the WTC's early years various governmental organizations became key tenants. It was not until the 1980s that the city's perilous financial state eased, after which an increasing number of private companies — mostly financial firms tied to Wall Street — became tenants.

Moreover, the trade center's "superblock", which replaced a more traditional, dense neighborhood, was regarded by some critics as an inhospitable environment that disrupted the complicated traffic network typical of Manhattan. For example, in his book The Pentagon of Power, the technical historian Lewis Mumford denounced the center as an "example of the purposeless giantism and technological exhibitionism that are now eviscerating the living tissue of every great city." Also, at the center of the complex, the immense Austin J. Tobin Plaza (named after the former executive director of the Port Authority of New York and New Jersey who oversaw the WTC's construction) was perpetually unpopular among citizens of New York.

The World Trade Center as viewed across the Hudson. Photo by Edgar de Evia.
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The World Trade Center as viewed across the Hudson. Photo by Edgar de Evia.
The World Trade Center as viewed from Queens
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The World Trade Center as viewed from Queens

However, the towers offered spectacular views from the observation deck (located on top of the South Tower) and the Windows on the World restaurant (located on top of the North Tower). The trade center had its many admirers, particularly visitors. For those who deemed it cold and sterile, there were just as many who appreciated its sheer grandeur; some even took advantage of it. French high wire acrobatic performer Philippe Petit walked between the towers on a tightrope in 1974, and Brooklyn toymaker George Willig scaled the south tower in 1977. Memorable moments such as these lent the World Trade Center a sense of humanity in ways that would forever be immortalized in New York City legend.

[edit] The complex

The WTC site building arrangement.
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The WTC site building arrangement.
The shadows of the World Trade Center over Manhattan.
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The shadows of the World Trade Center over Manhattan.

[edit] The Twin Towers

Each of the WTC towers had 110 stories. 1 WTC (the North Tower, which featured a massive 360 foot high TV antenna added in 1978) stood 1,368 feet (417 m) high,[6] and 2 WTC (the South Tower, which contained the observation deck) was 1,362 feet (415 m) high.[6] The length and breadth of the towers were 208 feet (63.4 m) x 208 feet (63.4 m). Although only Tower 1 featured an antenna, the structure of each building was designed to carry a broadcast mast. When completed in 1972, 1 WTC became the tallest building on Earth, unseating the Empire State Building after a 40 year reign. 2 WTC became the second tallest building in the world when completed in 1973. The difference in height between the two towers was because of a Port Authority request to have two floors, the 43rd and the 67th, in 1 WTC raised, the lower of the taller floors being a cafeteria for PANY workers. 2 WTC did not need these facilities, so it remained 1,362 feet. Regardless, the WTC towers held the height record only briefly. As the building neared completion in 1973, work had already begun on Chicago's Sears Tower, which ultimately reached 1,450 feet (442 m).[7]

1 World Trade Center and 2 World Trade Center under construction.
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1 World Trade Center and 2 World Trade Center under construction.

With the World Trade Center's destruction, the Empire State Building again became the tallest building in New York, after spending almost 30 years as the third-tallest in the city. The towers' sheer size was the subject of a joke during a press conference unveiling the landmarks. Minoru Yamasaki was asked: "Why two 110-story buildings? Why not one 220-story building?" His response was: "I didn't want to lose the human scale". Another popular joke among New York urbanites that died out late in the 1970s from overtelling was that the towers looked like the boxes the Chrysler Building and Empire State Building came in.

What the twin towers may have lacked in architectural aestheticism, they made up for with engineering innovation. To solve the problem of wind sway or vibration in the construction of the towers, chief engineer Leslie Robertson took a then unusual approach — instead of bracing the buildings corner-to-corner or using internal walls, the towers were essentially hollow steel tubes surrounding a strong central core. The 208 feet (63.4 m) wide facade was, in effect, a prefabricated steel lattice, with columns on 39 inch (100 cm) centers acting as wind bracing to resist all overturning forces; the central core took the majority of the gravity loads of the building. A very light, economical structure was built by keeping the wind bracing in the most efficient area, the outside surface of the building, thus not transferring the forces through the floor membrane to the core, as in most curtain-wall structures. The core supported the weight of the entire building and the outer shell containing 240 vertical steel columns called Vierendeel trusses around the outside of the building, which were bound to each other using ordinary steel trusses. In addition, 10,000 dampers were included in the structure. With a strong shell and core such as this, the exterior walls could be simply light steel and concrete. With the massive core and lightweight shell for structural integrity, Robertson created a tower that was extremely light for its size. This method of construction also meant that the twin towers had the world's highest load-bearing walls.[citation needed]

A typical floor layout and elevator arrangement of the WTC towers.
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A typical floor layout and elevator arrangement of the WTC towers.

The buildings were also the second supertall buildings to use sky lobbies (after the John Hancock Center in Chicago, Illinois),[8]which are floors where commuters can switch from an express elevator that goes only to the sky lobbies to a local elevator that goes to each floor in a section. The local elevators were stacked on top of each other, within the same elevator shaft. Located on the 44th and 78th floors of each tower, the sky lobbies enabled the elevators to be used efficiently while taking up a minimum of valuable office space.[9]

The World Trade Center viewed from the Empire State Building.
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The World Trade Center viewed from the Empire State Building.

Of the 110 stories, eight were set aside for technical services (mechanical floors) Level B6/B5, Floors 7/8, 41/42, 75/76 and 108/109, in four two-floor areas evenly spread up the building. All the remaining floors were free for open-plan offices. Each tower had 3.8 million square feet (350,000 ) of office space, ample room for companies to set up shop. Altogether the entire complex of seven buildings had 11.2 million square feet (1.04 km²) of space. During the 1990s some 500 companies, especially financial firms, had offices in the complex, including Morgan Stanley, Aon Corporation, Salomon Brothers, and the Port Authority itself. Electrical service to the towers was supplied by Consolidated Edison (ConEd) at 13,800 volts. This service passed through the WTC PDC or Primary Distribution Center and sent up through the core of the building to electrical substations located on the mechanical floors. The substations "stepped" the 13,800 primary voltage down to 480/277 volt secondary power and further to 120/208 volt general power and lighting service. The complex also was served by emergency generators located in the sublevels of the towers and on the roof of 5 WTC. [citation needed]

The lobby of the World Trade Center.
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The lobby of the World Trade Center.

The 110th Floor of 1 WTC (North Tower) housed commercial and public service radio & television transmission equipment. The roof of 1 WTC contained a vast array of transmission antennas including the center antenna mast rebuilt in 1999 by Dielectric Inc. to accommodate DTV. The mast contained the television signals for almost all NYC television broadcasters, (WCBS-TV, WNBC-TV, WNYW-TV, WABC-TV, WWOR-TV, WPIX-TV, WNET-TV, WPXN-TV, and WNJU-TV). It also had four NYC FM broadcasters on it as well (WPAT-FM, WNYC-FM, WKCR, and WKTU).[10] Access to the roof was controlled from the WTC Operations Control Center (OCC) located in the B1 level of 2 WTC. A series of electrically locked and monitored doors prevented unauthorized access.[citation needed] The World Trade Center complex was protected by an extensive fire detection and voice evacuation paging system upgraded after the 1993 bombing. Fire Command Stations, staffed by Fire Safety Directors were located in the lobbies of each building and the Operations Control Center (OCC) monitored these systems. An extensive study of the performance of World Trade Center Fire Protection Systems was conducted by the National Institute of Standards and Technology (NIST) following 9/11/2001.[11]

[edit] The other buildings

Five smaller buildings stood around the 16 acre (65,000 m²) block. One was the 22-floor Vista Hotel (3 WTC), later a Marriott Hotel, that was squeezed between the two towers. Three low-rise buildings (4 WTC, 5 WTC, and 6 WTC) in the same hollow tube design as the towers also stood around the plaza; they housed the US Customs Service and the US Commodities Exchange. In 1987, a 46-floor office building called 7 WTC was built north of the block. Under the block was a highly profitable underground shopping mall, which in turn led to various mass transit facilities, particularly the New York City subway system and the Port Authority's own PATH trains connecting Manhattan to Jersey City.

[edit] Site excavation

The excavation of the foundations of the WTC complex, known as the Bathtub, located on the former Radio Row, was particularly complicated since there were two subway tubes close by needing protection without service interruption. A six-level basement was built in the foundations. The excavation of about 1 million cubic yards (760,000 ) of earth and rock created a $90 million real estate asset for the project owner, the Port Authority of New York and New Jersey, which helped offset the enormous loss in revenues which came from the tax breaks given to the Trade Center itself. The soil was used to create 23 acres (93,000 m²) of landfill in the Hudson River next to the World Trade Center site, which became the site of Battery Park City (still under development).

One of the world's largest gold depositories was stored underneath the World Trade Center, owned by a group of commercial banks. The 1993 bomb detonated close to the vault, but it withstood the explosion, as did the towers. Seven weeks after the September 11th attacks, $230 million in precious metals were removed from basement vaults of 4 WTC, which included 3,800 100-Troy-ounce registered gold bars and 30,000 1,000-ounce silver bars.[12]

[edit] Engineers & contractors involved

  • Guy F. Tozzoli, Director World Trade Department
  • Rino M. Monti, Chief Engineer

Architects:

Structural engineers:

Foundation engineers:

Electrical engineers:

  • Joesph R. Loring & Associates, New York

Mechanical engineers:

  • Jaros, Baum & Bolles, New York

General contractor:

  • Tishman Realty & Construction Company, New York

[edit] Observation deck and Windows on the World

Although the majority of space in the WTC complex was off-limits to the general public, 1 WTC (North Tower) had a restaurant on the 107th floor called Windows on the World, and 2 WTC (South Tower) featured a public observation area aptly named "Top Of The World."

When visiting the observation deck, visitors would first pass through security checks added after the 1993 World Trade Center bombing. Next, visitors were whisked to the 107th floor indoor observatory and greeted with a 360 degree view of the New York City skyline, and exhibitions including a three-dimensional scale model of Manhattan, and a simulated helicopter ride around the city. Weather-permitting, visitors could take two short escalator rides up from the 107th floor and visit what was the world's highest outdoor viewing platform. At a height of 1,377 feet (420 m), visitors were able to take in a view of the North Tower and New York City unlike any other. On a clear day, it was claimed that visitors could see up to 45 miles (72 km) in any given direction. An anti-suicide fence was placed on the roof itself, with the viewing platform set back and elevated above it, requiring only an ordinary railing and leaving the view unobstructed.

Windows on the World was an elegant restaurant known as a place for big celebrations, such as weddings. In its last full year of operation, 2000, Windows reported revenues of $37.5 million United States dollars, making it the highest-grossing restaurant in the United States.

[edit] The Mall

[edit] February 13, 1975 fire

On February 13, 1975, the WTC North Tower was beset by a fire, which "burned at temperatures in excess of 700°C (1,292°F) for over three hours and spread over some 65 percent of the 11th floor, including the core, caused no serious structural damage to the steel structure. In particular, no trusses needed to be replaced".[13] Unlike in the September 11 collapse, in the 1975 fire outer support columns were not simultaneously severed such as by an aircraft collision.

[edit] February 26, 1993

On February 26, 1993 at 12:17 PM, a Ryder truck filled with 1,500 pounds (682 kg) of explosives was planted by Ramzi Yousef and detonated in the underground garage of the North Tower, opening a 100 foot (30 m) hole through 4 sublevels of concrete. Six people were killed and over one thousand injured.

Many people inside the North Tower were forced to walk down darkened stairwells which contained no emergency lighting, some taking two hours or more to reach safety. As the Port Authority was a bi-state agency, the towers were exempt from New York City building codes. Subsequent to the bombing The Port Authority installed emergency lighting in the stairwells. It is believed that this lighting saved many lives during the events of September 11, 2001.

In 1997 and 1998, six Islamist extremists were convicted and sentenced to life in prison for their roles in the bombing. According to a presiding judge, the conspirators' chief aim at the time of the attack was to de-stabilize the north tower and send it crashing into the south tower, toppling both landmarks.

As a memorial to the victims of the bombing of the tower, a reflecting pool was installed with the names of those who had been killed in the blast. Following the September 11, 2001 attacks, relief workers found a single fractured piece of this fountain; to date it is the only remaining part of the 1993 memorial that survived the collapse of the towers.

[edit] September 11, 2001

Seconds after American Airlines Flight 11 crashes into the North Tower.
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Seconds after American Airlines Flight 11 crashes into the North Tower.
United Airlines Flight 175 just before crashing into the South Tower.
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United Airlines Flight 175 just before crashing into the South Tower.
The World Trade Center on fire.
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The World Trade Center on fire.

On September 11, 2001 at 8:46 am, Al Qaeda suicide hijackers crashed American Airlines Flight 11 into the North Tower. [14][15] About twenty minutes later at 9:03 am, the hijackers crashed United Airlines Flight 175 into the South Tower,[15][16] which collapsed at 9:59 am. At 10:28 am the North Tower collapsed.[15] Later that day 7 World Trade Center also collapsed. The four remaining buildings in the WTC plaza also sustained heavy damage from debris and were ultimately demolished.

At the time of the incident, media reports suggested that tens of thousands might have been killed in the massacre, as on any given day upwards of 100,000 people could be inside the towers. Ultimately, 2,749 death certificates were filed relating to the WTC attacks, as of February 2005. Thirteen people died after the disaster from injuries received on September 11; three of these people died in Massachusetts, Missouri, and New Jersey, and the rest died in New York. Of these, 1,588 (58%) were forensically identified from recovered physical remains. The median age for the victims was 39 years (range: 2-85 years); the median age was 38 years for females (range: 2-81 years) and 39 years for males (range: 3-85 years). Three people were aged under 5 years, and three were aged over 80 years.[17][18]

Morgan Stanley was the largest tenant in the World Trade Center, with approximately 2,500 employees in the South Tower and 1,000 in the North Tower.[19]

For the following 8½ months, the World Trade Center site cleanup and recovery continued 24 hours a day and involved thousands of workers. The massive pile of debris smoked and smoldered for 99 days.

See also: Collapse of the World Trade Center, One World Trade Center tenants, Two World Trade Center tenants, and List of tenants in World Trade Center Seven

[edit] Rebuilding the World Trade Center

Current event marker This article or section contains information about expected future buildings or structures.
It is likely to contain information of a speculative nature and the content may change as the building approaches completion.
Hard hat
The completed new World Trade Center as it may look in 2012.
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The completed new World Trade Center as it may look in 2012.

The Lower Manhattan Development Corporation, the agency charged with coordinating the reconstruction of the World Trade Center site, selected the master plan, Memory Foundations by Daniel Libeskind,[20] which includes the 1776 ft (541 m) Freedom Tower. The height of 1,776 feet (541 m) was chosen as a reference to the year of American independence. A new 7 World Trade Center office building, which was not part of the site master plan, officially opened on May 23, 2006.

The Lower Manhattan Development Corporation sponsored an international design competition for the World Trade Center Memorial in spring 2003. The winning design, Michael Arad and Peter Walker's Reflecting Absence, was chosen in January 2004.

Ground Zero and the US Flag (2004)
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Ground Zero and the US Flag (2004)

The World Trade Center name will continue to be used as name of the site, as will the New York City Subway and PATH train stations that serve the complex. A temporary PATH station, largely following the layout of the original, is the first part of the complex to have re-opened.

On November 22, 2004, New York Governor George Pataki named the living former presidents as honorary members of the board rebuilding the World Trade Center.

On June 29, 2005, a redesigned Freedom Tower was unveiled which more closely resembled the character of the fallen towers. The new design also boasted several safety improvements over previous proposals.

On December 15, 2005, Sir Norman Foster was announced as the architect who will design the second of five new office towers planned for the site.

As of early 2006 progress at the World Trade Center site is slowly building up. Workers will soon move PATH train cables out of the way in order to start foundation work on both the Freedom Tower, permanent PATH station, underground parking and the Memorial. By the end of 2006, the site is finally expected to look like the massive construction project that built the previous WTC.

World Trade Center Site, June 2006.
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World Trade Center Site, June 2006.

On March 13, 2006 workers arrived at the World Trade Center site to remove remaining debris and start surveying work. This marks the official start of construction of the WTC Memorial and Museum.[21]

In April 2006, a tentative agreement was reached by the owner of the site, The Port Authority, and private developer Larry Silverstein. The main elements of that agreement are that Silverstein ceded rights to develop the Freedom Tower and Tower Five in exchange for financing with Liberty Bonds for Tower Two, Three, and Four which are considered to be the most marketable properties of the site. On April 27, 2006, a groundbreaking ceremony was held for the Freedom Tower.[22]

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 and a 85-foot tripod spire. Tower Three, or 175 Greenwich Street will have a roof height of 1,155 feet and an antennae height of 1,255 feet. Tower Four, or 150 Greenwich Street, will have an overall height of 946 feet.[23]

[edit] Site buildings

[edit] Original

[edit] New

[edit] Film and media

The World Trade Center has been featured in numerous films, as well as appearing in many television shows, cartoons, comic books and computer/video games. The pilot episode of The Lone Gunmen, aired in March 2001, featured a thwarted attempt to crash an airplane into the World Trade Center. Two major film dramatisations of the 9/11 attacks were released in 2006: United 93 and World Trade Center. Images of the clean-up process at Ground Zero were taken over nine months by photographer Joel Meyerowitz following 9/11, and have been compiled in Aftermath: World Trade Center Archive, published by Phaidon Press in 2006.

[edit] See also

[edit] Tenants

[edit] References

  1. ^ The Height of Ambition, New York Times September 8, 2002.
  2. ^ Port of New York and New Jersey (July 21, 2001). Governor Pataki, Acting Governor DiFrancesco Laud Historic Port Authority Agreement To Privatize World Trade Center. Press release.
  3. ^ Buildings.com. Four Percent of Manhattan's Total Office Space Was Destroyed in the World Trade Center Attack.
  4. ^ Lew, H. S., Richard W. Bukowski, and Nicholas J. Carino. Design, Construction, and Maintenance of Structural and Life Safety Systems (pdf). National Institute of Standards and Technology (NIST).
  5. ^ World Trade Center - Minoru Yamasaki. Greatbuildings.com. Retrieved on 2006-04-06.
  6. ^ a b World Trade Center, New York City. Emporis. Retrieved on 2006-04-13.
  7. ^ Sears Tower Building Information. Retrieved on 2006-09-11.
  8. ^ Otis History: The World Trade Center. Otis Elevator Company. Retrieved on 2006-12-07.
  9. ^ Gillespie, Angus K. (1999). “Chapter 2”, Twin Towers: The Life of New York City's World Trade Center. Rutgers University Press.
  10. ^ http://www.fcc.gov/
  11. ^ http://wtc.nist.gov/NISTNCSTAR1-4C.pdf
  12. ^ Rediff.com – Buried WTC gold returns to futures trade
  13. ^ New York Times. 15 February 1975.
  14. ^ N-Number Inquiry Results. Federal Aviation Administration.
  15. ^ a b c 9/11 Commission Report. The National Commission on Terrorist Attacks Upon the United States.
  16. ^ N-Number Inquiry Results. Federal Aviation Administration.
  17. ^ CNN. Identification of 9/11 remains comes to an end. Retrieved on February 23, 2005.
  18. ^ USA Today. NYC's work to ID 9/11 victims ends - for now. Retrieved on February 23, 2005.
  19. ^ Goldstein, Amy, Cheryl W. Thompson. "Jet Crash Victims' Stories Start To Emerge; Loved Ones Describe Lives, Last Contacts", The Washington Post, September 12, 2001.
  20. ^ Lower Manhattan Development Corp.. Selected Design for the WTC Site as of February 2003.
  21. ^ Westfeldt, Amy. "Construction Begins On World Trade Center Memorial", New York Sun, March 13, 2006.
  22. ^ Construction Begins at Ground Zero (AP story)
  23. ^ Designs Unveiled for Freedom Tower’s Neighbors

[edit] External links

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[edit] Webcams

Preceded by:
Empire State Building
Tallest Building in New York City
1973—2001
Succeeded by:
Empire State Building