World Trade Center History

Updated February 21, 2017 | Factmonster Staff

Magnificent buildings graced skyline

by David Johnson and Shmuel Ross
World Trade Center
World Trade Center Stats
  • 200,000 tons of steel
  • 425,000 cubic yards of concrete
  • 43,600 windows
  • 12,000 miles of electric cables
  • Had its own zip code, 10048
Each Tower:
  • Had 110 floors
  • 208 ft by 208 ft at base
  • Weighed 500,000 tons
  • 1,368 ft high (north tower)
  • 1,362 ft high (south tower)
  • Contained 198 miles of heating ducts
  • 97 elevators for passengers, 6 for freight

The twin towers of the World Trade Center were more than just buildings. They were proof of New York's belief in itself. Built at a time when New York's future seemed uncertain, the towers restored confidence and helped bring a halt to the decline of lower Manhattan. Brash, glitzy, and grand, they quickly became symbols of New York.

Rockefeller Brainchild

The World Trade Center was conceived in the early 1960s by the Downtown-Lower Manhattan Development Association to revitalize the seedy "Radio Row," dominated by electronic stores. Chase Manhattan Bank chairman David Rockefeller, founder of the development association, and his brother, New York governor Nelson Rockefeller, pushed hard for the project, insisting it would benefit the entire city.

In 1962, the Port Authority of New York and New Jersey began plans to build the center. Minoru Yamasaki and Associates of Michigan was hired as architect. Eventually, Yamasaki decided on two huge towers. Critics charged that a modern monolith would rob New York of character, ruin the skyline, disrupt television reception, and strain city services. However, the project was approved and construction began in 1966.

In order to create the 16-acre World Trade Center site, five streets were closed off and 164 buildings were demolished. Construction required the excavation of more than 1.2 million cubic yards of earth, which was used to create 23.5 acres of land along the Hudson River, now part of Battery Park City in lower Manhattan. During peak construction periods, 3,500 people worked at the site. A total of 10,000 people worked on the towers; 60 died during its construction.

Instant Landmarks

The north tower was opened in Dec. 1970 and the south tower in Jan. 1972; they were dedicated in April 1973. They were the world's tallest buildings for only a short time, since the Sears Tower in Chicago was completed in May 1973. However, the towers were ranked as the fifth and sixth tallest buildings in the world at the time of their destruction on Sept. 11, 2001.

Four smaller buildings and a hotel, all built nearby around a central landscaped plaza, completed the complex. The mall at the World Trade Center, which was located immediately below the plaza, was the largest shopping mall in lower Manhattan. The six basements housed two subway stations and a stop on the PATH trains to New Jersey.

Some 50,000 people worked in the buildings, while another 200,000 visited or passed through each day. The complex had its own zip code, 10048.

Previous Bombing

In 1993 terrorists drove a truck packed with 1,100 lbs of explosives into the basement parking garage at the World Trade Center. Despite the size of the blast—it left a crater 22 ft wide and 5 stories deep—only 6 people were killed and 1,000 injured. The towers were repaired, cleaned, and reopened in less than a month.

Night view of New York's Freedom Tower from the Hudson River

Night view of New York's Freedom Tower from the Hudson River

Rebuilding Plans

In 2002, separate design contests were held for rebuilding the World Trade Center site and creating a memorial for the victims of the attacks. The first round of finalists for the site, unveiled in July 2002, were widely criticized as being too boring and having too much of an emphasis on office space, leading to a new round of finalists in December.

In Feb. 2003, the Lower Manhattan Development Corporation, which was established by Governor Pataki to coordinate the various agencies and advisory committees involved in the rebuilding efforts, chose architect Daniel Libeskind's design for rebuilding the 16-acre site of the former World Trade Center. The design included a hanging garden, a memorial, a cultural center, and Freedom Tower, which would be a symbolic 1,776 feet tall from the ground to the top of its spire.

In July 2003, David Childs was brought in as the new lead architect of Freedom Tower, although Libeskind remained in charge of designing the site in general. The two had different visions for the tower; a design combining the approaches of both architects was unveiled in Dec. 2003. It would include wind turbines in its spire, designed to generate as much as 20% of the building's power.

On July 4, 2004, New York governor Pataki, New Jersey governor McGreevey, and New York City mayor Bloomberg laid the cornerstone for the Freedom Tower. The skyscraper, estimated to cost $1.5 billion, was expected to be ready for its first occupants by late 2008, while construction on the site in general is expected to last through 2015.

Just as construction was beginning, security concerns were raised, leading to a complete redesign of the tower. The new plans were released on June 29, 2005. The tower is to be moved further back from the street—and will have a cubic base the same size as each of the Twin Towers. The wind turbines have been eliminated. The design recalls that of the old buildings, while adding its own twists: starting with the square base, the tower's design moves into 8 isosceles triangles, creating an octagon at its center. An observation deck will sit at the 105th story, crowned by a parapet at exactly the height of the original Towers. An illuminated spire enclosing a television antenna will rise to the final height of 1776 ft.

Now called 1 World Trade, the former Freedom Tower will include 2.6 million square foot of office space, tenant amenities, restaurants, underground retail spaces, and access to transportation. 1 World Trade is scheduled to open in late 2013.

Michael Arad and Peter Walker's winning design 'Reflecting Absence'

Michael Arad and Peter Walker's winning design Reflecting Absence

Design for World Trade Center Memorial Selected

The Lower Manhattan Development Corporation announced in Jan. 2004 that architects Michael Arad and Peter Walker had won a competition to design the memorial to the people who died at the World Trade Center. There had been more than 5,000 entries in the competition.

The memorial, Reflecting Absence, would honor those who died at the World Trade Center in terrorist attacks on Sept. 11, 2001, and Feb. 26, 1993.

Reflecting Absence, which will be built where the Twin Towers once stood, includes two shallow pools surrounded by leafy trees. The names of the victims would be etched in walls around the pools.

"In its powerful, yet simple articulation of the footprints of the Twin Towers, Reflecting Absence has made the gaping voids left by the towers' destruction the primary symbol of loss," said Vartan Gregorian, who chaired the jury that chose the winner.

Plans for a new memorial on the site of One World Trade Center were redesigned in June 2006 to address security concerns, budgetary issues, and input from the victims' families. The central features—including the two pools fed by waterfalls—will be retained. The names of those killed in the attacks will be moved to the surrounding plaza, above ground.

Work began on the foundation in 2006 and was completed in fall 2007. Construction of the first structural framework began in 2007. The slurry wall, which held back the Hudson River during the Sept. 11th attacks, will be accessible for visitors to view from the 100,000 sf underground museum. Aboveground, more than 400 sweetgum and swamp white oak trees will surround the reflecting pools in the plaza, which is set to open Sept. 11, 2011. Completion of the museum is expected in 2013.

World Trade Center Transportation Hub

The Port Authority Trans-Hudson Transportation Hub (PATH) is expected to bring beauty and transport efficiency to Manhattan. PATH was designed by architect Santiago Calatrava to accommodate 250,000 pedestrians per day, which is the projected number of pedestrians for 2025. One of the innovative features of the design is that natural light will reach 60 feet below street level. The $3.8 billion hub will be the third largest transportation hub in NYC, will connect with 13 subway links, and is scheduled to open mid-2014.

The Office Towers

2 World Trade Center (2 WTC), 200 Greenwich St.: Designed by British architect Lord Norman Foster, this tower will rise 1,254 ft (78 stories) from a cruciform core. Characterized by a slanted roof designed to cast morning light on the memorial, 2 WTC will house 4 trading floors, 11.5 floors of building mechanics, 143,000 sf of retail space, and a sky lobby. While the building schedule is uncertain, as of now, the tower will be built to street level by mid-2012.

3 WTC, 175 Greenwich St.: Lord Richard Rogers designed this building, which will boast a diamond-shaped bracing pattern enclosing 2.8 million sf of office space and 5 floors of retail space and will rise 1170 ft (80 stories). The final construction schedule depends upon successful fundraising, but steel superstructure work began in April 2011.

4 WTC, 150 Greenwich St.: Architect Fumihiko Maki designed this final piece of the puzzle conceptualized by Daniel Libeskind. This 977 ft tower (72 stories) will form a descending spiral that carries the eye to the National 9/11 Memorial. It will house 1.8 million sf of office space, 146,000 sf of retail space, and access to transit. Like all the new WTC towers, Tower 4 will be LEED Gold certified by U.S. Green Building Council. Concrete is now being poured to floor 29 and is scheduled to open in 2013.

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