Rising to the clouds

The Burj Dubai, renamed Burj Khalifa, is the tallest free-standing structure on Earth -- taller than any communications and observation tower, taller than any television mast. It is astounding even by the standards of Dubai, the once-booming city-state that flaunts a palm-shaped island, a ski slope inside a shopping mall and a spinnaker-shaped skyscraper where tennis stars Roger Federer and Andre Agassi once staged a match on a helipad hundreds of feet above ground. Opening Monday after six years of construction and the recent Dubai debt crisis that shook world markets, the $1.5 billion, mixed-use tower was designed by Chicago architect Adrian Smith and his former colleagues at the Chicago office of Skidmore, Owings & Merrill (SOM).