Long known as Burj Dubai — Arabic for "Dubai Tower
Its backers wanted the skyscraper to be a monument to the boundless, can-do spirit of Dubai — one of a federation of seven small sheikdoms that make up the United Arab Emirates Dubai
Riding to the rescue was Sheik Khalifa bin Zayed Al Nahyan, the ruler of oil-rich neighbor Abu Dhabi , which pumped tens of billions of dollars into Dubai
As officials opened the tapering metal-and-glass spire with fireworks and multicolored lights, they unexpectedly announced it would be renamed Burj Khalifa, to honor the Abu Dhabi
Thousands of cheering, clapping spectators watched as a tally projected on huge screens at the opening ceremony revealed the tower's most closely guarded secret — its height of 2,717 feet. That made it more than 1,000 feet higher than the skyscraper known asTaipei 101 in Taiwan
The tallest building in the United States , the Willis Tower in Chicago World Trade Center Freedom Tower
The exact number of floors for the Burj Khalifa is not known, and could reflect how the developer chose to calculate the total.
Mohammed Alabbar, chairman of the tower's developer Emaar Properties, initially said Monday it had "more than 200" stories, but he later backtracked to more than 165 inhabitable floors, given its tapered top. Promotional materials sent before the tower's opening said it contained 160 stories.
Developers say they are confident in the safety of the tower, which is nearly twice the height of New York 's Empire State Building
Greg Sang, Emaar's director of projects, said the Burj Khalifa has "refuge floors" at 25 to 30 story intervals that are more fire resistant and have separate air supplies in case of emergency. Its reinforced concrete structure, he said, makes it stronger than steel-frame skyscrapers.
"A plane won't be able to slice through the Burj like it did through the steel columns of the World Trade Center
The tower was designed by Chicago-based Skidmore, Owings & Merrill, which has a long track record in engineering some of the world's tallest buildings, including the Willis Tower
Ahmed Elghazouli, a professor of structural engineering at Imperial College London who was not involved with the Burj's construction, said such groundbreaking buildings typically employ some of the world's best engineers, and go through more rigorous testing and require more studies during design than standard towers.
"I have no doubt that it has been looked after very well in terms of design and construction," he said when asked about the building's safety. "I would be much more comfortable getting into a building like this knowing that so much background work has gone into it."
With little oil of its own, Dubai
But like many overextended homeowners, the emirate and its state-backed companies borrowed too heavily and then struggled to keep up with payments as the financial crisis intensified and credit markets froze up.
The sheikdom shocked global markets last year when it unexpectedly announced plans to reorganize its main state-run conglomerate Dubai World and sought new terms in repaying some $26 billion in debt. It got some aid from Abu Dhabi
Dubai's hereditary ruler, Sheik Mohammed bin Rashid Al Maktoum, in recent months has increasingly spoken of the close relationship between the two emirates, declaring in November that "Dubai and Abu Dhabi are one" and will "be there for each other." Sheik Mohammed serves as vice president and prime minister of the UAE federation.
Analysts had questioned what Dubai might need to offer in exchange for the financial support it received from Abu Dhabi Abu Dhabi provided $25 billion last year as Dubai
"It's really quite remarkable to have to name your biggest and most memorable landmark after the living monarch of a neighboring emirate," said Christopher Davidson, a professor at the University of Durham
Burj developer Emaar is also partly owned by the Dubai government, but is not part of struggling Dubai World, which has investments ranging from Dubai
Emaar's Alabbar said the landmark Burj is 90 percent sold in a mix of residential units, offices and other space, offering a counterpoint to Dubai
At their peak, some apartments in the Burj were selling for more than $1,900 per square foot, although they now can go for less than half that, said Heather Wipperman Amiji, chief executive of Dubai
Amiji said some buyers may struggle to find tenants at going rates once the tower's expected high service charges are factored in.
The building ranks as the world's tallest structure, beating out a television mast in North Dakota
Early designs for the Burj had it edging out Taipei
"We weren't sure how high we could go," said Baker, of Skidmore, Owings & Merrill. "It was kind of an exploration ... a learning experience."
Work began in 2004 and moved rapidly. At times, new floors were being added almost every three days. During the busiest construction periods, some 12,000 people worked at the tower each day, according to Emaar. Low-wage migrant workers from the Indian subcontinent provided much of the muscle.
The Burj is the centerpiece of a 500-acre development that officials hope will become a new central residential and commercial district in this sprawling and often disconnected city. It is flanked by dozens of smaller but new skyscrapers and the Middle East 's largest shopping mall.
That layout — as the core of a lower-rise skyline — lets the Burj stand out prominently against the horizon. It is visible across dozens of miles of rolling sand dunes outside Dubai
An observation deck on the 124th floor opens to the public Tuesday, with adult tickets starting at 100 dirhams, or just over $27 apiece. The ride to the top took just over a minute during a visit for journalists Monday.
The Burj itself cast a sundial-like shadow over low-rise houses and empty sand-covered lots stretching toward the azure Persian Gulf .
