The Freedom Tower

The design of the building, a work in progress ever since plans to rebuild at the World Trade Center site,  has been completed, owners of the property say.The design of the building that will occupy the former World Trade Center is done and it will stand 1,776 feet over lower Manhattan and will open in 2012.

The design incorporates lessons learned from the horrific events of September 11, 2001 when over 2,500 people died in the New York City attacks, according to the website NYC-Tower.com, with interconnected redundant exits, a chemical and biological air filtration system, a dedicated firefighter staircase, superior fireproofing, pressurized and widened stairwells and special safety areas on each floor.

The 2.6 million square foot building has a base dimension of 200 by 200 square feet and a rooftop height of 1,368 feet with a 408-foot high antenna on top, according to the website. The design also includes a memorial dedicated to those who died in the terrorist attacks.

The original twin World Trade Center towers, completed in 1973, had 110 floors supported by 244 vertical columns that surrounded a central core of elevators, stairwells and building mechanical systems, according to an article by Jackie Craven that appeared in About.com.

While critics posed questions about the structural stability of the original towers, the fact remains that no skyscraper is built to withstand the impact of a commercial jet liner flying at 500 miles per hour. Furthermore, the World Trade Center survived the 1993 truck bombing that, according to those who orchestrated the attack, was supposed to topple at least one of the buildings.

http://architecture.about.com/od/disastersandcollapses/a/twintowerfall.htm

http://www.nyc-tower.com/