Willis Tower

The **Willis Tower**, formerly known as the **Sears Tower**, is a 108-story,  skyscraper in Chicago, Illinois. The tower has 108 stories, though the building's owners count the main roof as 109 and the mechanical penthouse roof as 110. When it finished construction in 1973, it beat the World Trade Center in New York City to become the tallest building in the world. It was the tallest building in the world for twenty-five years until the Petronas Towers were built in Malaysia. It was also the tallest building in the Western Hemisphere for 41 years, until the new One World Trade Center beat it in 2013.

Willis Tower is seen as the best work of architect Fazlur Khan. As of 2021, it is the third-tallest building in the United States and the Western hemisphere. It is also the 23rd-tallest in the world. Each year, more than one million people visit its observation deck, the highest in the United States. It is one of Chicago's most popular tourist places. The tower was renamed in 2009 after the Willis Group bought the tower.

The building's largest office partner is United Airlines, which moved its corporate headquarters from 77 West Wacker Drive in 2012. Other major company offices in the tower include Schiff Hardin and Seyfarth Shaw.

## History 
### Planning and construction 
In 1969, Sears, Roebuck & Co. was the largest retailer in the world, with about 350,000 employees. Sears wanted to put many of its employees into one building on the western part of Chicago's Loop. Sears eventually bought the West Chicago loop location and bought 15 old buildings from 100 owners and paid $2.7 million to the city. Sears and the city of Chicago approved the design and construction began in April 1971. 
Sears needed  of office space for its planned tower. They hired architects Skidmore, Owings & Merrill (SOM). Sears paid for construction of the building. Architects Bruce Graham and Fazlur Khan designed the building. All nine tubes would rise up to the 50th floor of the building, where the northwest and southeast tubes end. The northeast and southwest tubes reach the 66th floor with the north, east, and south tubes end at the 90th. The system became successful in skyscraper construction and has been used in most supertall buildings.

With the floors left over Sears decided to rent them to other companies for offices. Small metal floors were added to give enough space to people working in the tower. The height was limited by the Federal Aviation Administration (FAA) to protect air traffic.  Two antennas were added at the top of the building for television and radio broadcasting. The building was completed in May 1973 and opened the next year.

Black bands appear on the tower around the 29th–32nd, 64th–65th, 88th–89th, and 104th–108th floors. These give the building's environmental support systems and hide its belted trusses. There are around 40,000 sprinkler heads in the building. They cost $4 million.

In February 1982, two television antennas were added to the building, increasing its total height to . The lawsuits said that above the 67th floor would make television signals bad.

The Illinois Citizens' Committee for Broadcasting wanted the Federal Communications Commission (FCC) to stop the building from getting taller. On May 26, 1972, the Commission did not take action as they did not have the power to do anything. In the 2000s, many companies in the tower began to leave because of terrorist threats or because they found better office spaces. Their solution was to create a new entrance, which became known as "Lunchbox Entrance". Sears wanted to sell the building in the late 1980s. Sears talked about the loan again in 1994. Just two years later, Sears began to move out of the tower to Hoffman Estates, Illinois.
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However, in 1997, the Canadian company TrizecHahn bought AEW's holdings of the building for $110&nbsp;million. After the September 11 attacks, two of the largest office partners, Goldman Sachs and Merrill Lynch, quickly announced plans leave the building's 300,000&nbsp;ft2 space. In 2003, Trizec sold its holdings of the tower to MetLife for $9&nbsp;million.

In 2004, MetLife sold the building to a group of investors from New York City and Skokie, Illinois. The price was $840&nbsp;million, with $825&nbsp;million held in a mortgage.

In June 2006, seven men were arrested by the FBI and charged with plans to destroy the tower. The case went to court in October 2007. After three trials, five of the suspects were convicted and two acquitted. The leader of the group, Narseal Batiste, was sentenced to 13.5 years in prison. In response to the possible threat of an attack, the building's largest company space at this time, Ernst & Young, moved to North Wacker Drive in early 2009.

Since 2007, the owners had thought about building a hotel on the north side of the building.

In February 2009, the owners announced they were thinking about painting the building silver, an idea that was later stopped.

In 2015, the Blackstone Group bought the tower for a reported $1.3&nbsp;billion, the highest price ever paid for a U.S. property outside of New York City. In 2017, Blackstone announced a $500 million renovation for the building, such as building a six-story commercial area in the tower's plaza area.

In May 2020, after many days of raining, the building's three basement levels were flooded.

### Naming rights
Sears' naming rights ended in 2003, but the building was still called the Sears Tower for many years. On July 16, 2009, the building was officially renamed the Willis Tower. On August 13, 2012, United Airlines said they were moving its corporate headquarters from 77 West Wacker Drive to Willis Tower. Many Chicagoans still call the tower by its old name. A July 2009 CNN article showed some Chicagoans did not want to call the tower by its new name. An October 2010 article from *Chicago* magazine called the building one of Chicago's 40 most important things. *Time* magazine called the name change one of the top 10 worst corporate name changes.

### Climbing
On May 25, 1981, Dan Goodwin climbed the tower while using suction cups and wearing a Spider-Man costume. Goodwin was arrested at the top after the seven-hour climb and was later charged with trespassing.

In August 1999, Alain "Spiderman" Robert climbed the building all the way to the top using only his hands and feet.

Since 2009, the Willis Tower has hosted SkyRise Chicago, the world's tallest indoor stair climb as a charity event.

## Details and height
Skidmore architects designed the Willis Tower to have large floors of  in the lower part of the building.

From the ground to the top of the taller antenna, Willis Tower is  tall. The observation deck elevators are the fastest in the world at  per minute. With clear weather, four states can be seen from the observation deck: Michigan, Indiana, Illinois, and Wisconsin. 

The Willis Tower is the third tallest building in the Americas (after One World Trade Center and Central Park Tower) and the Western Hemisphere. With a height of  with its antenna, it is the third-tallest freestanding structure in the Americas and eighth-tallest freestanding structure in the world.

On November 8, 2013, architects in Chicago and New York City started talking about the height of the One World Trade Center. They were saying that Willis Tower might be taller.

At the bottom, the lowest level of Willis Tower is 43 feet below elevation. Many broadcast station transmitters are built at the top of Willis Tower. About 1.7 million tourists visit the tower every year. A second observation deck on the 99th floor was made as a backup and for private events. 

In January 2009, work to improve the Skydeck began, such as adding glass balconies that go  outside of the building. On May 29, 2014, the laminated glass flooring of one of the boxes broke while visitors were inside. Nobody was hurt. The flooring on that same box cracked on June 12, 2019.

## Awards 
The U.S. Environmental Protection Agency (EPA) gave the tower ENERGY STAR certification in 2018 for good energy efficiency. 

## Related pages
* List of tallest buildings in Chicago
* List of tallest buildings in the world

## References
## Other websites 
* Official website
* Chicago Skydeck website 
* Emporis.com - Willis Tower
* SkycraperPage.com – Willis Tower
* A view from 103rd floor of the tower