One World Trade Center
The topping off of One World Trade center was delayed due to weather. Reuters

The final topping of One World Trade Center was postponed today due to weather-related circumstances. The tower was scheduled to reach its final height Monday, but high winds prevented the tower from reaching its final height of 1776 feet.

"The Port Authority of New York and New Jersey says the spire pieces and a steel beacon will be lifted at a later date from the rooftop to cap the building at 1,776 feet," the Associated Press reports.

One World Trade Center has been under construction since April 27, 2006, and is expected to be completed and open in late 2013, 12 years after the events of 9/11 that brought down the Twin Towers.