World Trade Center (1973–2001)

Long ago, many tall buildings were built in New York.

These were called the Twin Towers. They were very tall.

A man named Minoru Yamasaki designed them. He wanted them to look good. The buildings had many floors for work.

People used special elevators to go up. These elevators worked like fast trains. They helped people move quickly.

One man even walked on a rope between them. This was a very brave thing to do.

Today, there is a new place there. It has a park and a museum. It is a special place to visit.

The World Trade Center was a group of seven buildings.

It sat in New York City. A man named David Rockefeller had the idea for it. He wanted to help the city grow.

Minoru Yamasaki was the lead architect. He designed the famous Twin Towers.

These two towers were very tall. They were the tallest in the world when they were finished. The towers had many small windows. This made people feel safe inside.

To move people up, they used a new elevator system. These elevators used "sky lobbies."

These were special floors where people could switch elevators. This worked like a fast train.

On September 11, 2001, a very sad event happened. Two planes hit the towers. This caused the buildings to fall. Many people died that day.

A new complex is being built now. It has six new skyscrapers. There is also a museum and a park. Two large pools mark where the old towers once stood.

The original World Trade Center was a large group of seven buildings.

It sat in the Financial District of Lower Manhattan in New York City. This place was a huge center for business and money. The complex was meant to hold about 130,000 people. It was a symbol of the economic power of the United States. Many people around the world saw it as a sign of global trade.

Moving people through such huge buildings was a big job. The architects used a special elevator system to make it work. They created "sky lobbies" on the 44th and 78th floors.

These floors worked like a subway system. People could take a fast express elevator to a sky lobby. Then, they switched to a local elevator to reach their specific floor. This smart idea saved a lot of space for offices. There were 95 elevators in total to help everyone move.

Building the complex took many years of planning and hard work. David Rockefeller suggested the idea to help Lower Manhattan grow.

His brother, Nelson Rockefeller, was the governor of New York at the time. The Port Authority of New York and New Jersey led the project. They had to move a neighborhood called Radio Row to make space. This area was full of electronics stores and warehouses. Construction began in the late 1960s and continued through 1975. The buildings were officially dedicated on April 4, 1973.

The most famous parts were the two Twin Towers.

The North Tower was 1,368 feet tall. The South Tower was 1,362 feet tall. They were the tallest buildings in the world when they were finished. They remained the tallest twin skyscrapers until 1996. Minoru Yamasaki was the lead architect who designed them. He used narrow windows to help people feel more secure. The towers were so famous they appeared in 472 different films.

On September 11, 2001, a very tragic event changed the site forever. Two Boeing 767 jets were flown into the Twin Towers. The fires from the fuel caused the towers to collapse. This led to the destruction of the other buildings in the complex. Today, a new World Trade Center is being built in the same area. It includes six new skyscrapers and a large memorial.

Two square reflecting pools now mark where the towers once stood.

The original World Trade Center (WTC) was a massive complex of seven buildings.

It was located in the Financial District of Lower Manhattan in New York City. The complex served as a major economic center for the United States. It was intended to symbolize globalization and American economic prosperity. The complex was designed to hold an estimated 130,000 people.

It stood as a landmark of modern architecture and international business.

Building the complex required complex negotiations and massive urban changes. In the 1940s and 1950s, economic growth was mostly in Midtown Manhattan. David Rockefeller suggested building the complex to help Lower Manhattan grow. The Port Authority of New York and New Jersey led the project. To make room, the Port Authority had to remove a neighborhood called Radio Row.

This area was a busy district of electronics stores and warehouses. The Port Authority purchased the properties starting in March 1965. Demolition of Radio Row was completed by the end of 1966.

Architect Minoru Yamasaki designed the buildings with specific functional goals. He wanted to provide a massive amount of office space. His original plan for 80-story towers was expanded to 110 stories.

This change was necessary to meet the Port Authority's space requirements. Yamasaki used a square plan for the buildings. Each side of the towers was approximately 207 feet long. He also designed narrow windows to help occupants feel more secure. The facades were clad in an aluminum-alloy material.

Moving thousands of people required a unique engineering solution for the elevators. Taller buildings usually need many elevator shafts, which takes up office space. Yamasaki and his engineers used a system of "sky lobbies."

These were special floors located on the 44th and 78th levels. People took large-capacity express elevators to these lobbies. Then, they switched to local elevators to reach their specific floors. This method increased usable office space from 62 percent to 75 percent. The complex used a total of 95 elevators.

The most iconic structures were the 110-story Twin Towers. The North Tower, or 1 World Trade Center, stood 1,368 feet tall. The South Tower, or 2 World Trade Center, stood 1,362 feet tall. They were the tallest buildings in the world when they were completed. They remained the tallest twin skyscrapers until 1996. The towers were famous in popular culture and appeared in 472 films.

In 1974, Philippe Petit even performed a tightrope walk between them.

Despite its fame, the complex faced several serious security incidents. A fire occurred in 1975, and a bombing happened in 1993.

A bank robbery also took place in 1998. On September 11, 2001, al-Qaeda-affiliated hijackers flew two Boeing 767 jets into the towers. Between 16,400 and 18,000 people were in the Twin Towers during the strikes.

The burning jet fuel intensified fires and damaged structural columns. This ultimately caused both towers to collapse.

The destruction of the towers caused a chain reaction across the site. Falling debris and fires in nearby buildings led to the collapse of the other WTC buildings. This included 7 World Trade Center. The event also caused catastrophic damage to 10 other large structures nearby. The total death toll in and around the towers was 2,606 people. The cleanup and recovery process lasted eight months. On May 30, 2002, the last piece of WTC steel was ceremonially removed.

A new World Trade Center complex is currently being built on the site. It includes six new skyscrapers and several other buildings. One World Trade Center is the tallest building in the Western Hemisphere. It stands 1,776 feet tall and opened in November 2014.

A memorial and museum now honor those who were killed. The memorial features two large square reflecting pools. These pools mark the exact locations where the Twin Towers once stood.