The John Hancock Center is a 100-story, 1,128-foot supertall skyscraper located in Chicago, Illinois. Located in the Magnificent Mile district, the building was officially renamed 875 North Michigan Avenue in 2018. The skyscraper was designed by Peruvian-American chief designer Bruce Graham and Bangladeshi-American structural engineer Fazlur Rahman Khan of Skidmore, Owings and Merrill (SOM). When the building topped out on May 6, 1968, it was the second-tallest building in the world after the Empire State Building, and the tallest in Chicago. It is currently the fifth-tallest building in Chicago and the thirteenth-tallest in the United States, behind the Aon Center in Chicago and ahead of the Comcast Technology Center in Philadelphia. When measured to the top of its antenna masts, it stands at . The building is home to several offices and restaurants, as well as about 700 condominiums, and at the time of its completion contained the highest residence in the world. The building was named for John Hancock Mutual Life Insurance Company, a developer and original tenant of the building, which itself was named for the U.S. Founding Father John Hancock. In 2018, John Hancock Insurance, years after leaving the building requested that its name be removed and the owner is seeking another naming rights deal. From the 95th-floor restaurant, diners can look out at Chicago and Lake Michigan. The observatory (360 Chicago), which competes with the Willis Tower's Skydeck, has a 360° view of the city, up to four states, and a distance of over . 360 Chicago is home to TILT, a moving platform that leans visitors over the edge of the skyscraper to a 30-degree angle, a full bar with local selections, Chicago's only open-air SkyWalk, and also features free interactive high-definition touchscreens in six languages. The 44th-floor sky lobby features America's highest indoor swimming pool. History 20th century The project, which would become the world's second tallest building at opening, was conceived and owned by Jerry Wolman in late 1964. The project was financed by John Hancock Mutual Life Insurance Company. Construction of the tower was interrupted in 1967 due to a flaw in an innovative engineering method used to pour concrete in stages, that was discovered when the building was 20 stories high. The engineers were getting the same soil settlements for the 20 stories that had been built as what they had expected for the entire 99 stories. This forced the owner