The idea of building a tower to
touch the sky goes back thousands of years. And within the past century, architects and engineers have designed seemingly impossible structures that stand a quarter-mile high -- a tribute to humanity's need to test the limits, as well as a way to alleviate congestion in crowded cities. But after terrorists crashed two hijacked passenger planes into New York City's tallest buildings on September 11, leveling both of the Twin Towers, iconic skyscrapers around the world suddenly gained a new label: target.
That shift has inspired builders with a new goal-creating the safest tall building in the world. In the aftermath of the recent tragedy, the brightest minds in architecture and structural engineering are pooling their expertise to figure out how a building can survive the newest forms of terrorism. Will novel kinds of concrete be able to withstand bomb blasts and the 2,000-degree temperatures of a jet fuel fire? Can sensitive laser detectors enable a building's emergency staff to locate poisonous chemical agents before they even reach the building? Is it possible to create a fireproof evacuation system that will enable people on the top floors to descend to safety when the middle of the building is in flames? The answers to these questions and many others may be coming soon to a skyscraper near you.