The idea of a world trade center, first conceived by city leaders in New York who wanted to create a headquarters for international commerce, was not realized for years until 1960, when the Downtown-Lower Manhattan Association, with strong support by government and civic leaders, recommended that the Port Authority build such a center.

After determining the feasibility of the project, the Port Authority received authorization in 1962 and began plans for a complex of some 15 million square feet of office, retail and meeting space. While initial interest was to build on a site along the East River in Lower Manhattan, final plans rested on developing a parcel on the west side where the Hudson and Manhattan Railroad Terminal Buildings stood, and for the Port Authority to operate the commuter rail system, later renamed the Port Authority Trans-Hudson (PATH) line. The new complex would incorporate a replacement of the Hudson and Manhattan Railroad Terminal and offer immediate access to several subway lines.

The Port Authority selected Detroit-based architect Minoru Yamasaki as principal designer; the final design for The World Trade Center was unveiled in January 1964 with twin 110-story towers rising above a central plaza and five smaller buildings on the 16-acre site. The vision for The World Trade Center was, perhaps, best expressed at the dedication ceremony by Yamasaki when he said, “World trade means world peace and The World Trade Center buildings in New York… have a bigger purpose than just providing room for tenants. The World Trade Center is a living symbol of man’s dedication to world peace.”

Construction at the site began in 1966, and The World Trade Center, including the Twin Towers, was officially dedicated on April 4, 1973. To view The World Trade Center Dedication Ceremony program, click here. Built during a troubled time when, an energy crisis crippled New York and international trade, and Midtown assumed Lower Manhattan’s prestige as the financial center of the city, the two magnificent towers inspired a renewed surge of energy and The World Trade Center project helped bring a halt to the decline of Lower Manhattan.

Containing more than four million square feet each, the towers exemplified the use of many engineering and design innovations including their core structures and elevator systems. The glass and steel towers were the first skyscrapers ever built without the use of masonry, as well as the first to use “tube” construction in which the outside walls – a structural exoskeleton – were load bearing, eliminating the need for columns. Each wall section was hoisted into place by “Kangaroo” cranes that advanced upward atop each tower as the steel rose, jumping to the next elevated position by hydraulic jacks. To see how The World Trade Center was constructed, please click here.

The two towers stood at 1368 (1 WTC) and 1362 (2 WTC) feet and were the tallest buildings in the world at the time they were completed. Simple, slender, silver and soaring, the aesthetics of the Twin Towers showed daring and restored confidence; and they became the key recognizable elements of the Manhattan skyline. They were more than just buildings — they were proof of New York’s belief in itself.

A suite of seven-story buildings known as 4 WTC, 5 WTC and 6 WTC (the U.S. Customs House), also designed by architect Minoru Yamasaki, framed the central plaza. The Vista International Hotel, 3 WTC, designed by Skidmore, Owings & Merrill, was completed in 1981. It was the first hotel to open in Lower Manhattan since 1836. Added in 1987, the 47-story 7 WTC, designed by Emery Roth and Sons connected to The World Trade Center complex by a plaza-level pedestrian bridge. A larger pedestrian bridge connected The World Trade Center with the Winter Garden atrium of the World Financial Center, across West Street. The complex was so large, that it had its own zip code, 10048.

Occupied by many export-oriented and blue chip international tenants, as well as the World Trade Centers Association, The World Trade Center would, over the years, become one of the world’s most glamorous business addresses. The success of The World Trade Center in New York encouraged many others to be built throughout the US and the world, and by the late 1990s, there were almost 300 centers in major cities in 88 countries.

On any given day, approximately 50,000 people worked in the towers with another 200,000 passing through as visitors. International and local students attended the World Trade Institute, and tourists and New Yorkers alike visited the Observation Deck and the famous Windows of the World restaurant in the thousands every day.

The central plaza that was originally designed by Yamasaki as a “contemplative” space, was later named the Austin J. Tobin Plaza, after the executive director of the Port Authority who initiated the development of The World Trade Center. During almost any season, workers, residents and visitors would walk through the Plaza and enjoy a variety of events ranging from outdoor concerts to art exhibits and outdoor dining. Much pedestrian activity also took place under the Plaza in the shopping concourse which connected PATH and subways and the center’s buildings. Featuring 80 stores, it became one of the most successful malls in the United States.

In 1998, plans were approved by the Port Authority to privatize The World Trade Center. The culmination of this process was a historic agreement signed on July 24, 2001 by Silverstein Properties, Inc.’s (SPI) and Westfield America Inc., to lease the office and retail space of The World Trade Center. The 99-year lease was New York City’s richest real estate deal $3.2 billion and was one of the largest privatizations in history.

The history of The World Trade Center is marred by two terrorist attacks.

In 1993, a group of terrorists left a van loaded with explosives in an underground parking garage adjacent to One World Trade Center. Six people and one unborn child died and more than a thousand were injured from the resulting explosion.  The explosion created a five-story crater beneath the towers and resulted In hundreds of millions of dollars In damage. The Towers were repaired and reopened on March 19 — less than a month's time - due to round-the-clock efforts by The Port Authority of New York and New Jersey.  The entire recovery effort took more than a year.  In response to the bombing, the Port Authority spent a total of $250 million between 1993 and 2001 In physical, structural and technological Improvements to the complex, as well as training and composition of the WTC response staff.

On September 11, 2001, nineteen Al Qaeda terrorists hijacked four commercial aircrafts to strike the World Trade Center again and various targets in Washington, D.C.  American Airlines flight 11—a  Boeing 767 carrying 87 people (including crew, excluding hijackers) bound from Boston to Los Angeles—was deliberately crashed into the north face of the North Tower between floors 94-98. United Flight 175—a Boeing 767 carrying 60 people (including crew, excluding hijackers) bound from Boston to Los Angeles—was deliberately crashed into the south face of the South Tower between floors 78-84. American Airlines Flight 77—a Boeing 757 carrying 59 people (including crew, excluding hijackers) bound from Washington DC to Los Angeles—was deliberately crashed into the west wall of the Pentagon in Washington, DC. United Airlines Flight 93—a Boeing 757 carrying 44 people (including crew, excluding hijackers)—was crashed in defeat into an empty field in Shanksville, Pennsylvania, after passengers, learning of the other attacks, launched a counter-attack against the hijackers to seize control of the aircraft. The South Tower of the WTC collapsed 56 minutes after it was hit. The North Tower collapsed 102 minutes after it was hit.[See timeline]

The impact of the planes on the WTC towers killed all on board the aircrafts, hundreds of people in the towers, and left hundreds trapped or in imminent danger. The crash of the first plane alone triggered the largest response operation in New York City history, mobilizing the New York City fire department, the Port Authority police department, Port Authority civilian responders, and the New York City police department at their highest levels, as well as all on-duty WTC fire safety and security personnel, New York City’s Office of Emergency Management, and numerous other local, state and federal agencies. Many civilians also voluntarily came to the aid of others and in many cases lost their lives.

Within approximately half an hour of the first attack, all local bridges, tunnels, highways and airports were closed; nearby subway and PATH terminals were shut down and evacuated; sensitive locations around the city were secured and government buildings were evacuated.Within an hour, bus service was suspended in the northeast region; Amtrak stopped commuter train service nationwide; all US flights were halted; military fighters had established combat air patrol over New York City.

The collapse of the towers killed nearly all who remained alive inside, including hundreds of first responders, and many in the underground concourse, the Marriott hotel, and in the nearby vicinity, as well as trapping and injuring many. Of the 17,400 people estimated to have been in the towers at the time of the first attack, more than 15,000 were able to safely evacuate the buildings, including approximately 3,000 who left the South Tower in the seventeen minutes before it was hit.

The attacks on the WTC resulted in a total of 2,750 fatalities (excluding the terrorists) injury to hundreds, and the complete destruction of all seven World Trade Center buildings, as well as damage to structures in the vicinity. The FDNY, which lost 343 of its members, suffered the largest loss of life of any emergency response agency in history. The PAPD, which lost 37 of its members, suffered the largest loss of life of any police force in history. The NYPD, which lost 23 of its members, suffered the second largest loss of life of any police force in the history (second to the number of PAPD fatalities on that day).

The attack on the Pentagon killed all on board Flight 77 and 125 people on the ground, including 55 military service members and 70 civilians. A total of 184 were killed (excluding hijackers) and 106 were seriously injured. Within minutes, a major rescue, fire and medical response was initiated and overseen by the Arlington County fire department. Because the event was a terrorist attack, the FBI became the lead federal agency in charge. Within ten minutes of the crash, the White House and US Capitol were evacuated. Combat air patrol was also established over the DC area that morning.

The crash of United Airlines Flight 93 killed all on board and likely prevented the deaths of many on the ground, as well as the destruction of a significant US landmark; it was later determined by the 9-11 Commission that Flight 93 was intended to hit either the US Capitol or the White House.
In total, 2,974 people (excluding the terrorists)were killed by the September 11 attacks, the largest loss of life as a result of a hostile attack on American soil in history.

To view the timeline of events of that day including two other associated terrorist hijackings, please click here.

Immediately after the WTC towers fell, a major rescue and recovery operation was initiated at the WTC site and Fresh Kills Landfill, including round-the-clock participation by thousands of civilians and city, state, and federal officials. Of the unknown number of people who initially survived the collapse of the towers, approximately 20 were rescued or able to self-extricate from the debris field. The last survivor was found just after 12:30 p.m. on September 12. The rescue and recovery, supported by tens of thousands of civilian volunteers, lasted for nine months and was concluded with a public Last Column removal ceremony on May 30, 2002.

The recovery of the Pentagon took approximately two months and reconstruction of the damaged section was completed by September 2002. The rebuilding of lower Manhattan continues today under the auspices of the Lower Manhattan Development Corporation and the Port Authority.

In the aftermath of September 11, donations of money, services, thoughts and prayers were sent from near and far. Numerous organized and spontaneous memorials and vigils were held in New York City and Washington, DC, as well as across the country and the globe.

Memorials dedicated to the victims of September 11 have been established around the country. The National September 11 Memorial & Museum will build the permanent Memorial and Museum at the World Trade Center dedicated to the attacks of September 11, 2001 and February 26, 1993.

For New Yorkers, the Twin Towers were a daily landmark — an anchor for one’s place in a familiar environment. And for visitors, they were symbols of a dynamic New York. For the rest of the world, The World Trade Center was a world famous address, and immediately recognizable as symbols of New York City. There is no aspect of the life of New York City that has not been touched by the destruction of The World Trade Center and its powerful absence.

A new chapter in the history of The World Trade Center began with the rebuilding. After the clean up of the site, the Port Authority began construction of a temporary WTC PATH Station and repaired PATH infrastructure. PATH service between New Jersey and Lower Manhattan was restored and opened for service November 24, 2003.

In 2003, the Lower Manhattan Development Corporation (LMDC), established by then New York Governor Pataki to coordinate the various parties involved in the rebuilding efforts, chose a redevelopment plan conceived by Studio Daniel Libeskind. It calls for the creation of a memorial and memorial museum as the centerpiece of the site. Surrounding the six-acre memorial space will be The WTC Transportation Hub, One World Trade Center/Freedom Tower, towers 2, 3, and 4, retail development, cultural facilities and new open spaces. New streets, created by restoring Greenwich Street to run north-south and Fulton Street to run east-west through the site, as well as enhanced sidewalks will facilitate the flow of activity in a renewed complex.

Architects Michael Arad and Peter Walker were selected to design the WTC Memorial from more than 5,000 entries. The memorial will honor those who died at The World Trade Center in terrorist attacks on September 11, 2001, and February 26, 1993. The design, “Reflecting Absence,” refined in 2006, includes two fountains, which will be built where The Twin Towers once stood, as well as an underground Memorial Museum. The WTC Memorial, which is currently being constructed by the Port Authority, is scheduled to open in 2010.

The WTC Transportation Hub is designed by the Downtown Design Partnership, a joint venture of DMJM Harris and STV, Inc., in association with world famous architect Santiago Calatrava.

Currently under construction, the hub will replace the temporary WTC PATH Station when complete, accommodating some 250,000 pedestrians per day. This future architectural landmark will be the centerpiece of a transportation network that links New Jersey with downtown Manhattan — seamlessly linking PATH with 13 subway lines. It is scheduled to be completed in 2011.

Designed by David Childs of Skidmore, Owings & Merrill, The Freedom Tower (One World Trade Center) will be the tallest of five planned towers. When complete, the Tower will stand 1,776 feet tall including a 408 feet high spire. A restaurant and an observation deck are planned for the top floors. Towers 2, 3 and 4 are being developed by SPI, the leaseholder for the commercial space. Designs were unveiled in 2006 for these proposed towers, which will descend in height from the Freedom Tower and, together with the Freedom Tower, encircle the planned memorial. Towers 2 and 3 were designed respectively by British architects Norman Foster and Richard Rogers and Japanese architect Fumihiko Maki. Towers 3 and 4 are scheduled to be open in 2011. One World Trade Center, The Freedom Tower, and Tower 2 are scheduled to open in 2012.

As envisioned in the redevelopment master plan, a fifth tower on a southern parcel outside of the original 16-site will be developed and occupied by JP Morgan Chase & Co. Also located outside the site is 7 World Trade Center. Designed by David Childs, 7 World Trade Center was rebuilt by SPI and opened in 2006.

When the rebuilding of The World Trade Center site is complete, it will be one of the most important developments of this century. Significant in its symbolism will be the memory of what The World Trade Center once was, and the reason why it was rebuilt. There will be nothing else like it in the world.