express elevators are not accessible from floors within the express zone, a team of firefighters had to break through a brick wall from the parking garage to extricate the passengers, none of whom suffered injuries. Elevators to the 95th/96th floor were closed thereafter pending investigation. Subsequent investigation documented only a controlled descent from the 20th floor to the 11th floor. A piece of cladding fell from the building on January 5, 2022. Architecture One of the most famous buildings of the structural expressionist style, the skyscraper's distinctive X-braced exterior shows that the structure's skin is part of its "tubular system". This is one of the engineering techniques which the designers used to achieve a record height; the tubular system is the structure that keeps the building upright during wind and earthquake loads. This X-bracing allows for both higher performance from tall structures and the ability to open up the inside floorplan. Such original features have allowed 875 North Michigan Avenue to become an architectural icon. It was pioneered by Bangladeshi-American structural civil engineer Fazlur Khan and chief architect Bruce Graham. The interior was remodeled in 1995, adding to the lobby travertine, black granite, and textured limestone surfaces. The elliptical-shaped plaza outside the building serves as a public oasis with seasonal plantings and a 12-foot (3.7 m) waterfall. A band of white lights at the top of the building is visible all over Chicago at night, and changes colors for different events. For example, at Christmas time the colors are green and red. When a Chicago-area sports team goes far in the playoffs, the colors are changed to match that team's colors. The building is a member of the World Federation of Great Towers. It has won various awards for its distinctive style, including the Distinguished Architects Twenty-five Year Award from the American Institute of Architects in May 1999. In celebration of the 2018 Illinois Bicentennial, the John Hancock Center was selected as one of the Illinois 200 Great Places by the American Institute of Architects Illinois component (AIA Illinois) and was recognized by USA Today Travel magazine, as one of AIA Illinois' selections for Illinois 25 Must See Places. The building is only partially protected by a fire sprinkler system, as the residential floors do not have sprinklers. Including its antennas, the building has a height of , making it the thirty-third tallest building in the world when measured to