World Trade Center in New York City
The original World Trade Center was a complex with seven buildings featuring landmark twin towers in Lower Manhattan, New York City, United States. The complex opened on April 4, 1973, and was destroyed in 2001 during the September 11 attacks. The site is currently being rebuilt with five new skyscrapers and a memorial to the casualties of the attacks. , only one skyscraper has been completed, with four more expected to be completed before 2020. One World Trade Center will be the lead building for the new complex and is expected to be finished by 2013. A sixth tower is still awaiting confirmation to be built. At the time of their completion, the original 1 and 2 World Trade Center were the tallest buildings in the world.
The complex was designed in the early 1960s by Minoru Yamasaki and Associates of Troy, Michigan, and Emery Roth and Sons of New York. The twin 110-story towers used a tube-frame structural design. To gain approval for the project, the Port Authority of New York and New Jersey agreed to take over the Hudson & Manhattan Railroad, which became the Port Authority Trans-Hudson (PATH). Groundbreaking for the World Trade Center took place on , 1966. The North Tower (1) was completed in and the South Tower (2) was finished in . The construction project involved excavating a large amount of material, which was later used as landfill to build Battery Park City on the west side of Lower Manhattan. The cost for the construction was $400 million ($ in 2011 dollars). The complex was located in the heart of New York City's downtown financial district and contained 13.4 million square feet (1.24 million m2) of office space. The Windows on the World restaurant was located on the 106th and 107th floors of 1 World Trade Center (the North Tower) while the Top of the World observation deck was located on the 107th floor of 2 World Trade Center (the South Tower). Other World Trade Center buildings included the Marriott World Trade Center; 4 World Trade Center; 5 World Trade Center; 6 World Trade Center, which housed the United States Customs. All of these buildings were built between 1975 and 1981. The final building constructed was 7 World Trade Center, which was built in 1985. The second King Kong was filmed in 1976 with some scenes mentioning and showing the World Trade Center. The World Trade Center experienced a fire on , 1975, and a bombing on , 1993. In 1998, the Port Authority decided to privatize the World Trade Center, leasing the buildings to a private company to manage, and awarded the lease to Silverstein Properties in .
On the morning of September 11, 2001, Al-Qaeda-affiliated hijackers flew two 767 jets into the complex, one into each tower, in a coordinated terrorist attack. After burning for 56 minutes, the South Tower (2) collapsed, followed a half-hour later by the North Tower (1), with the attacks on the World Trade Center resulting in 2,753 deaths. 7 World Trade Center collapsed later in the day and the other buildings, although they did not collapse, had to be demolished because they were damaged beyond repair. The process of cleanup and recovery at the World Trade Center site took eight months. The first new building at the site was 7 World Trade Center, which opened in . The Lower Manhattan Development Corporation (LMDC), established in to oversee the rebuilding process, organized competitions to select a site plan and memorial design. Memory Foundations, designed by Daniel Libeskind, was selected as the master plan, which included the 1776 ft One World Trade Center, three office towers along Church Street and a memorial designed by Michael Arad.
Planning and construction
The idea of establishing a World Trade Center in New York City was first proposed in 1943. The New York State Legislature passed a bill authorizing New York Governor Thomas E. Dewey to begin developing plans for the project but the plans were put on hold in 1949. During the late 1940s and 1950s, economic growth in New York City was concentrated in Midtown Manhattan, while Lower Manhattan was left out. To help stimulate urban renewal, David Rockefeller suggested that the Port Authority build a World Trade Center in Lower Manhattan.
Initial plans, made public in 1961, identified a site along the East River for the World Trade Center. As a bi-state agency, the Port Authority required approval for new projects from the governors of both New York and New Jersey. New Jersey Governor Robert B. Meyner objected to New York getting a $335 million project. Toward the end of 1961, negotiations with outgoing New Jersey Governor Meyner reached a stalemate. With the new location and Port Authority acquisition of the H&M Railroad, New Jersey, agreed to support the World Trade Center project.
Approval was also needed from New York City Mayor John Lindsay and the New York City Council. Disagreements with the city centered on tax issues. On , 1966, an agreement was reached that the Port Authority would make annual payments to the City in lieu of taxes for the portion of the World Trade Center leased to private tenants. In subsequent years, the payments would rise as the real estate tax rate increased.
On September 20, 1962, the Port Authority announced the selection of Minoru Yamasaki as lead architect and Emery Roth & Sons as associate architects. Yamasaki devised the plan to incorporate twin towers; Yamasaki's original plan called for the towers to be 80 stories tall. To meet the Port Authority's requirement for 10000000 sqft) of office space, the buildings would each have to be 110 stories tall.
A major limiting factor in building height is the issue of elevators; the taller the building, the more elevators are needed to service the building, requiring more space-consuming elevator banks. This system was inspired by the New York City Subway system whose lines include express stations where both express and local trains stop and local stations where only local trains stop.
Yamasaki's design for the World Trade Center, unveiled to the public on , 1964, called for a square plan approximately 208 ft in dimension on each side. Yamasaki's design included building facades sheathed in aluminum-alloy. The World Trade Center was one of the most striking American implementations of the architectural ethic of Le Corbusier and it was the seminal expression of Yamasaki's gothic modernist tendencies.
In addition to the twin towers, the plan for the World Trade Center complex included four other low-rise buildings, which were built in the early 1970s. The 47-story 7 World Trade Center building was added in the 1980s to the north of the main complex. Altogether, the main World Trade Center complex occupied a 16 acre superblock.
The structural engineering firm Worthington, Skilling, Helle & Jackson worked to implement Yamasaki's design, developing the tube-frame structural system used in the twin towers. The Port Authority's Engineering Department served as foundation engineers, Joseph R. Loring & Associates as electrical engineers, and Jaros, Baum & Bolles as mechanical engineers. Tishman Realty & Construction Company was the general contractor on the World Trade Center project. Guy F. Tozzoli, director of the World Trade Department at the Port Authority, and Rino M. Monti, the Port Authority's Chief Engineer, oversaw the project. As an interstate agency, the Port Authority was not subject to local laws and regulations of the City of New York including building codes. Nonetheless, the structural engineers of the World Trade Center ended up following draft versions of the new 1968 building codes. The tube-frame design, earlier introduced by Fazlur Khan, was a new approach that allowed more open floor plans than the traditional design that distributed columns throughout the interior to support building loads. The World Trade Center towers used high-strength, load-bearing perimeter steel columns called Vierendeel trusses that were spaced closely together to form a strong, rigid wall structure, supporting virtually all lateral loads such as wind loads, and sharing the gravity load with the core columns. The perimeter structure containing 59 columns per side was constructed with extensive use of prefabricated modular pieces each consisting of three columns, three stories tall, connected by plates. The spandrel plates were welded to the columns to create the modular pieces off-site at the fabrication shop. Adjacent modules were bolted together with the splices occurring at mid-span of the columns and spandrels. The spandrel plates were located at each floor, transmitting shear stress between columns, allowing them to work together in resisting lateral loads. The joints between modules were staggered vertically so the column splices between adjacent modules were not at the same floor. The trusses connected to the perimeter at alternate columns and were on 6 foot 8 inch (2.03 m) centers. The top chords of the trusses were bolted to seats welded to the spandrels on the exterior side and a channel welded to the core columns on the interior side. The floors were connected to the perimeter spandrel plates with viscoelastic dampers that helped reduce the amount of sway felt by building occupants.
Hat trusses (or "outrigger truss") located from the 107th floor to the top of the buildings were designed to support a tall communication antenna on top of each building. Groundbreaking for the construction of the World Trade Center took place on , 1966.
The site of the World Trade Center was located on landfill with the bedrock located 65 ft below. To construct the World Trade Center, it was necessary to build a "bathtub" with a slurry wall around the West Street side of the site, to keep water from the Hudson River out. The slurry method selected by Port Authority's chief engineer, John M. Kyle, Jr., involved digging a trench, and as excavation proceeded, filling the space with a "slurry" mixture composed of bentonite and water, which plugged holes and kept groundwater out. When the trench was dug out, a steel cage was inserted and concrete was poured in, forcing the "slurry" out. It took fourteen months for the slurry wall to be completed; it was necessary before excavation of material from the interior of the site could begin. The 1.2 million cubic yards (917,000 m3) of material excavated were used (along with other fill and dredge material) to expand the Manhattan shoreline across West Street to form Battery Park City.
In January 1967, the Port Authority awarded $74 million in contracts to various steel suppliers, and Karl Koch was hired to erect the steel. Tishman Realty & Construction was hired in to oversee construction of the project. Construction work began on the North Tower in ; construction on the South Tower was underway by . The original Hudson Tubes, carrying PATH trains into Hudson Terminal, remained in service as elevated tunnels during the construction process until 1971 when a new PATH station opened.
The topping out ceremony of 1 WTC (North Tower) took place on , 1970, while 2 WTC's ceremony (South Tower) occurred later on , 1971. The ribbon cutting ceremony was on , 1973.
Plans to build the World Trade Center were controversial. The site for the World Trade Center was the location of Radio Row, home to hundreds of commercial and industrial tenants, property owners, small businesses, and approximately 100 residents, many of whom fiercely resisted forced relocation. A group of small businesses affected filed an injunction challenging the Port Authority's power of eminent domain. The case made its way through the court system to the United States Supreme Court; the Court refused to accept the case.
Private real estate developers and members of the Real Estate Board of New York, led by Empire State Building owner Lawrence A. Wien, expressed concerns about this much "subsidized" office space going on the open market, competing with the private sector when there was already a glut of vacancies. Others questioned whether the Port Authority really ought to take on a project described by some as a "mistaken social priority".
The World Trade Center design brought criticism of its aesthetics from the American Institute of Architects and other groups. Weather permitting, visitors could take two short escalator rides up from the 107th floor viewing area to an outdoor viewing platform on the 110th floor at a height of 1377 ft. On a clear day, visitors could see up to 50 mi. Aside from the main restaurant, two offshoots were located at the top of the North Tower: "Hors d'Oeuvrerie" (offered a Danish smorgasbord during the day and sushi in the evening) and "Cellar in the Sky" (a small wine bar). Windows on the World also had a wine school program run by Kevin Zraly. Windows on the World was closed following the 1993 World Trade Center bombing.
The 1995 PCA world chess championship was played on the 107th floor of the South Tower.
In January 1998, Mafia member Ralph Guarino, who had gained maintenance access to the World Trade Center, arranged a three-man crew for a heist that netted over $2 million from a Brinks delivery to the eleventh floor of the World Trade Center.
February 13, 1975 fire
On February 13, 1975, a three-alarm fire broke out on the 11th floor of the North Tower. Fire spread through the core to the 9th and 14th floors by igniting the insulation of telephone cables in a utility shaft that ran vertically between floors. Areas at the furthest extent of the fire were extinguished almost immediately and the original fire was put out in a few hours. Most of the damage was concentrated on the 11th floor, fueled by cabinets filled with paper, alcohol-based fluid for office machines, and other office equipment. Fireproofing protected the steel and there was no structural damage to the tower. Other than the damage caused by the fire, a few floors below suffered water damage from the extinguishing of the fires above. At that time, the World Trade Center had no fire sprinkler systems.
February 26, 1993 bombing
On February 26, 1993, at 12:17 p.m., a Ryder truck filled with 1500 lb of explosives, planted by Ramzi Yousef, detonated in the underground garage of the North Tower. The blast opened a 100 foot (30 m) hole through five sublevels with the greatest damage occurring on levels B1 and B2 and significant structural damage on level B3. Six people were killed and 50,000 other workers and visitors were left gasping for air within the 110 story towers. Many people inside the North Tower were forced to walk down darkened stairwells that contained no emergency lighting, some taking two hours or more to reach safety.
Yousef fled to Pakistan after the bombing but was arrested in Islamabad in , and was extradited back to the United States to face trial. Sheikh Omar Abdel Rahman was convicted in 1996 for involvement in the bombing and other plots. Yousef and Eyad Ismoil were convicted in for their carrying out the bombing. Four others had been convicted in for their involvement in the 1993 bombing. According to a presiding judge, the conspirators' chief aim at the time of the attack was to destabilize the north tower and send it crashing into the south tower, toppling both landmarks.
Following the bombing, floors that were blown out needed to be repaired to restore the structural support they provided to columns. The slurry wall was in peril following the bombing and loss of the floor slabs that provided lateral support against pressure from Hudson River water on the other side. The refrigeration plant on sublevel B5, which provided air conditioning to the entire World Trade Center complex, was heavily damaged. Subsequent to the bombing, the Port Authority installed photoluminescent markings in the stairwells. The fire alarm system for the entire complex needed to be replaced because critical wiring and signaling in the original system was destroyed. 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. However, the memorial was destroyed following the attacks. Names of the victims of the 1993 bombing are included in the National September 11 Memorial & Museum.
In 1998, the Port Authority approved plans to privatize the World Trade Center. In 2001, the Port Authority sought to lease the World Trade Center to a private entity. Bids for the lease came from Vornado Realty Trust, a joint bid between Brookfield Properties Corporation and Boston Properties, and a joint bid by Silverstein Properties and The Westfield Group. By privatizing the World Trade Center, it would be added to the city's tax rolls The damage caused to the north tower by Flight 11 destroyed any means of escape from above the impact zone, trapping 1,344 people. Flight 175 had a much more off-centered impact compared to Flight 11, and a single stairwell was left intact; however, only a few people managed to pass through it successfully before the tower collapsed. Although the south tower was struck lower than the north tower, thus affecting more floors, a smaller number, fewer than 700, were killed instantly or trapped. At 9:59 a.m., the South Tower collapsed after burning for approximately 56 minutes. The fire caused steel structural elements, already weakened from the plane impact, to fail. The north tower collapsed at 10:28 a.m., after burning for approximately 102 minutes.
At 5:20 p.m. owing to uncontrolled fires causing structural failure. 3 World Trade Center, a Marriott hotel, was destroyed during the collapse of the two towers. The three remaining buildings in the WTC plaza sustained heavy damage from debris and were ultimately demolished. The Deutsche Bank Building across Liberty Street from the World Trade Center complex was later condemned owing to the uninhabitable toxic conditions inside; it was deconstructed, with work completed in early 2011. The Borough of Manhattan Community College's Fiterman Hall at 30 West Broadway was also condemned owing to extensive damage in the attacks and is slated for deconstruction.
In the immediate aftermath of the attacks, media reports suggested that tens of thousands might have been killed in the attacks, as on any given day over 50,000 people could be inside the towers. Ultimately, 2,753 death certificates (excluding those for hijackers) were filed relating to the 9/11 attacks, including one filed for Felicia Dunn-Jones, who was added to the official death toll in ; Dunn-Jones died five months later from a lung condition linked to exposure to dust during the collapse of the World Trade Center. Three other victims were then added to the official death toll by the city medical examiner's office: Dr. Sneha Anne Philip, who was last seen the day before the attacks; Leon Heyward, a man who developed lymphoma and subsequently died in 2008 as a result of dust ingestion during the events following the attacks to the Twin Towers; and Jerry Borg, who died in December 2010 of pulmonary sarcoidosis determined in June 2011 to be the result of dust from the attacks. 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 ; 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 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 1776 ft 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 entitled Reflecting Absence was selected in .
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 , 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 , 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 , 2006. Tower Two, or 200 Greenwich Street, will have a roof height of 1254 ft and a 96 ft tripod spire for a total of 1350 ft. Tower Three, or 175 Greenwich Street will have a roof height of 1,155 feet (352 m) and an antenna height reaching 1255 ft. Tower Four, or 150 Greenwich Street, will have an overall height of 946 ft. On , 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 currently 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 and Two's foundations are becoming visible, and Tower Three 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. However construction will be complete on Tower Two on time, given that numerous American and Chinese companies are "very interested" in leasing space at the WTC. 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.
Controversy and criticism
There was much debate regarding the future of Ground Zero following the destruction of the World Trade Center. Disagreement and controversy regarding who owned the property and what would be built there hindered construction at the site for several years. Many wanted the Twin Towers to be rebuilt, but stronger and taller. This movement was led by an informal organization called the Twin Towers Alliance. Others, considering the area sacred, did not want anything built there at all or wanted the entire site to become a memorial. Finally, a master plan was agreed upon, which would feature a memorial and museum where the original twin towers stood and six new skyscrapers surrounding it.
One World Trade Center itself has been met with criticism. The original design, which was asymmetrical, significantly shorter, and called for an off-center spire, was met with much disapproval, causing a new one to be devised. A key feature of the final design, the fortified, windowless base, was also denounced as looking dreary and unwelcoming. To alleviate this problem, the designers decided to clad it with prismatic glass panels. Since the failure of that plan, it is now unclear what the base will be covered with. The name change from Freedom Tower to One World Trade Center was met with some criticism. Governor of New York George Pataki stated in 2003 that, "The Freedom Tower isn't going to be One World Trade Center, it's going to be the Freedom Tower."
WTC American flags
A small number of American flags which flew on or near the WTC during the attacks were recovered during the clean-up efforts. One was found at 5:30 a.m. on the morning of , 2001, by New York City Police Sergeant Gerald Kane and Detective Peter Friscia. While assisting rescue teams at "Ground Zero", they noticed that the large American flag that once flew in front of the WTC at Church Street had been blown off the flagpole during the collapse of the buildings and was tangled upside down on a streetlight several feet away. The two men recruited a number of soldiers and firefighters in the area who hoisted a ladder to the top of the streetlight. Detective Friscia climbed the rungs of the ladder to the top, untangled and retrieved the flag and brought it down to the ground. Kerik later released the flag to NASA officials and it was transported aboard the space shuttle Endeavour (STS-108) as part of its –17, 2001, mission to the International Space Station. On Flag Day, , 2002, the American flag was returned to the people of New York City by Sean O'Keefe of NASA and Commander Dom Gorie and the crew members of the Endeavour, in a ceremony at the Rose Center at the American Museum of Natural History. The flag is secured and maintained by New York City's Commissioner of Records and is part of the annual 9/11 ceremony at Ground Zero.
Another flag, which had originally flown atop one of the towers, was recovered three days after the attacks and, owing to its poor condition, was turned over to the National Guard for its ceremonial destruction. The National Guard then discovered from a label that the flag was the property of the Port Authority, and instead of retiring the flag, returned it. It was then used during the memorial service of several first responders, and was flown during both the 2001 World Series and Super Bowl XXXVI. The flag was also used, controversially, in the Opening Ceremony of the 2002 Winter Olympics held in Salt Lake City. Initially the International Olympic Committee (IOC) refused to allow the flag to be used in ceremony, fearing it would be seen as too pro-American, overly patriotic, and create complications during future ceremonies. But an agreement was eventually reached between the event organizers and the IOC, which allowed the flag to be carried into Rice-Eccles Olympic Stadium by both U.S. athletes and 9/11 first responders. The flag was carried into the stadium in silence, after which the flag bearers paused in front of the Mormon Tabernacle Choir, allowing them to sing The Star-Spangled Banner, while a separate American flag was raised.
A number of flags from other countries were also recovered from the World Trade Center site. A New Zealand flag was presented to the then Prime Minister of New Zealand, Helen Clark, by representatives of the New York City Fire Department. Two of the casualties were New Zealanders. Conservators mounted and framed the flag and it now hangs in the main stairwell of Parliament House, the main building of the New Zealand Parliament Complex. A Union flag of the United Kingdom was also recovered, and is now housed at the Imperial War Museum North in Manchester, England. The United Kingdom suffered the most casualties after the United States, with around 60 to 70 Britons killed during the attacks.
In popular culture
The World Trade Center was an iconic structure and has been featured in numerous films as well as appearing in many television shows, cartoons, comic books, video games and music videos.
- Project Rebirth
- The Sphere
- The Philippe Petit High Wire Walk Between the Towers
- World Trade Center – Silverstein Properties
- World Trade Center – Port Authority of New York & New Jersey
- World Trade Center Progress – Port Authority of New York & New Jersey
- National September 11 Memorial & Museum at the World Trade Center
- Building the Twin Towers: A Tribute – slideshow by Life magazine
- New York: A Documentary film features the construction and destruction of the World Trade Center in the seventh and final episode of the series directed by Ric Burns.
- Historic video with scenes of World Trade Center under construction in 1970