One World Trade Center, the giant monolith being built to replace the twin towers destroyed in the Sept. 11 attacks, will lay claim to the title of New York City's tallest skyscraper today. Workers will erect steel columns that will make its unfinished skeleton a little over 1,250 feet high, just enough to peak over the roof of the observation deck on the Empire State Building.
The milestone is a preliminary one. Workers are still adding floors to the so-called "Freedom Tower," and it isn't expected to reach its full height for at least another year, at which point it is likely to be declared the tallest building in the U.S. and third tallest in the world.
Those bragging rights, though, will carry an asterisk.
Crowning the world's tallest buildings is a little like picking the boxing champion. There is often disagreement about who deserves the belt.
In this case, the issue involves the 408-foot-tall needle that will sit on the tower's roof.
Count it, and the World Trade Center is back on top. Otherwise, it will have to settle for No. 2, after the Willis Tower in Chicago.
"Height is complicated," said Nathaniel Hollister, a spokesman for the Council on Tall Buildings and Urban Habitats, a Chicago-based organization considered an authority on such records.
Experts and architects have long disagreed about where to stop measuring super-tall buildings outfitted with masts, spires and antennas that extend far above the roof.
Consider the case of the Empire State Building: Measured from the sidewalk to the tip of its needlelike antenna, the granddaddy of all super-tall skyscrapers actually stands 1,454 feet high, well above the mark being surpassed today by One World Trade Center.
Purists, though, say antennas shouldn't count when determining building height.
An antenna, they say, is more like furniture than a piece of architecture. Like a chair sitting on a rooftop, an antenna can be attached or removed. The Empire State Building didn't even get its distinctive antenna until 1952. The record books, as the argument goes, shouldn't change every time someone installs a new satellite dish.
Excluding the antenna brings the Empire State Building's total height to 1,250 feet. That was still high enough to make the skyscraper the world's tallest from 1931 until 1972.
The same factors apply to measuring the height of One World Trade Center.
Designs call for the tower's roof to stand at 1,368 feet -- the same height as the north tower of the original World Trade Center. The building's roof will be topped with a 408-foot, cable-stayed mast, making the total height of the structure a symbolic 1,776 feet.