The original World Trade Center was a complex of seven buildings featuring landmark twin towers in Lower Manhattan, New York City. The complex opened on April 4, 1973, and was destroyed in 2001 during the September 11 attacks. The site is being rebuilt with five new skyscrapers and a memorial to the casualties of the attacks. At the time of their completion, 1 and 2 World Trade Center were the tallest buildings in the world, surpassing the Empire State Building, also in Manhattan.

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 August 5, 1966. The North Tower (1) was completed in December 1972 and the South Tower (2) was finished in July 1973. 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 ($2,169,167,354 in 2011 dollars).

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 May 2006. The Lower Manhattan Development Corporation (LMDC), established in November 2001 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 1,776-foot (541 m) One World Trade Center, three office towers along Church Street and a memorial designed by Michael Arad.

The Sphere is a large metallic sculpture by German sculptor Fritz Koenig, currently displayed in Battery Park, New York City, that once stood in the middle of Austin J. Tobin Plaza, the area between the World Trade Center towers in Manhattan. After being recovered from the rubble of the Twin Towers after the September 11, 2001 attacks, the artwork faced an uncertain fate, and it was dismantled into its components. Although it remained structurally intact, it had been visibly damaged by debris from the airliners that were crashed into the buildings and from the collapsing skyscrapers themselves.

Six months after the attacks, following a documentary film about the sculpture, it was relocated to Battery Park on a temporary basis — without any repairs — and formally rededicated with an eternal flame as a memorial to the victims of 9/11. It has become a major tourist attraction, due partly to the fact that it survived the attacks with only dents and holes.

The Teardrop Memorial was given to the United States from the Country of Russia as a gift.  It is dedicated "To The Struggle Against World Terrorism".

This memorial stands across the Bay from NYC in Bayonne, New Jersey.

Zurab Tsereteli is the Russian Artist who designed the bronze statue.  It stands 100 feet high and weighs about 175 tons.  He got the idea for the sculpture as the events unfolded on that very day.

There are 9 pathways that lead to the sculpture and the base has 11 sides.  Engraved on the base are the thousands of names who perished on that horrible day.  The body resembles a tall tower and its center is a large jagged tear with a shiny teardrop dangling down the middle.  The teardrop itself weighs 4 tons and is 40 feet in length.  The teardrop represents the immense sadness felt around the world.

United Airlines Flight 93 was United Airlines' scheduled morning transcontinental flight across the United States from Newark International Airport in Newark, New Jersey, to San Francisco International Airport in California. On Tuesday, September 11, 2001, the Boeing 757–222 aircraft operating the route was hijacked by four al-Qaeda terrorists as part of the September 11 attacks. It subsequently crashed into a field in Stonycreek Township, Pennsylvania near Shanksville during an attempt by some of the passengers to regain control.

The hijackers breached the aircraft's cockpit and overpowered the flight crew approximately 46 minutes after takeoff. Ziad Jarrah, a trained pilot, then took control of the aircraft and diverted it back toward the east coast of the United States. Although the evidence remains inconclusive, it is widely presumed the intended target was the United States Capitol in Washington, D.C. An alternative suggestion has been the White House, possibly in hopes of killing then-president George W. Bush. That morning, however, the president was visiting an elementary school in Florida.

After the hijackers had taken control of the plane, several passengers and flight attendants were able to make telephone calls and learn that attacks had been made on the World Trade Center in New York and the Pentagon in Virginia. As a result, some of the passengers decided to mount an attempt to regain control of the aircraft. During the attempt, however, the plane crashed into a field in Stonycreek Township, near Shanksville in Somerset County, Pennsylvania, about 80 miles (130 km) southeast of Pittsburgh and 150 miles (240 km) northwest of Washington, D.C. All on board, including the four hijackers, were killed. Many witnessed the impact from the ground and news agencies began reporting the event within an hour.

Subsequent analysis of the flight recorders recovered from the crash site revealed how the actions taken by the passengers prevented the aircraft from reaching the hijackers' intended target. Of the four aircraft hijacked on September 11 – the others were American Airlines Flight 11, American Airlines Flight 77 and United Airlines Flight 175 – United Airlines Flight 93 was the only one that failed to reach its hijackers' intended target.