The Chicago Spire is a supertall skyscraper under construction in Chicago, Illinois. The skyscraper will become North America’s tallest free-standing structure and the world’s tallest all-residential building, eventually standing taller than Chicago’s Sears Tower and New York’s upcoming Freedom Tower, as well as Toronto’s CN Tower. The building was designed by Spanish architect Santiago Calatrava and is being developed by Garrett Kelleher of Shelbourne Development Group, Inc. The Chicago Spire is scheduled to be completed in 2011 with 150 floors.