Willis Tower (formerly known as the Sears Tower) is a 110 story building in the heart of Chicago’s downtown. Willis Tower is not only one of the tallest buildings in the world, it is also a magnificent icon, impossible to miss within Chicago’s skyline.
In 1969, Sears Roebuck and Company was the largest retailer in the world, with about 350,000 employees. They decided they needed one large office space for their many employees. Architects Skidmore, Owings and Merrill were commissioned to design what would become one of the largest office buildings in the world. Fazlur Khan, the structural engineer, designed the “bundled tube” design that handled both wind and gravity.
In August, 1970 ground was broken for the beginning of construction. Taking three years to complete, Sears Tower was finished in May 1973. The builders used enough concrete to make an eight- lane highway five miles long. Within the building, there are 25 miles of plumbing, 1500 miles of electric wiring , 80 miles of elevator cable, 796 restroom faucets, and more than 145,000 light fixtures. The last beam put in place was signed by 12,000 construction workers, Sears employees and Chicagoans.
In 1988, Sears Roebuck and Company sold and moved out of the building, but the Sears Tower name remained until 2009 when the building was renamed after the Willis Group, a London- based global insurance broker.
Skydeck Chicago is the observation deck on the 103rd floor of the building. Approximately 1.3 million tourists visit Skydeck Chicago every year. On a clear day, you can see over 50 miles in each direction and see four states. The elevators within the building are among some of the fastest in the world, operating as fast as 1,600 feet per minute. In 2009, Skydeck Chicago opened its newest attraction, The Ledge, 4 glass boxes that extend 4.3 feet outside the Tower and stand 1,353 feet above Wacker Drive. With glass on the ceiling, floor, and all sides, it is truly, an unforgettable experience.