New York

The 12th anniversary of the 9/11 attacks is the first that will see One World Trade Center, formerly known as Freedom Tower, topping out at a symbolic 1,776 feet. After years of missteps and inaction, the building's completion, now scheduled to take place in early 2014, will be a welcome end to a fraught project that has long weighed on the national consciousness. Yet just as construction costs have ballooned to nearly $4 billion, making this by far the most expensive new office building in the world, its developers—the...