Since the public opening on April 4, 1973, New York's iconic Twin Towers remained a symbol of the city up until the tragic September 11 attacks. Take a look back at the iconic structures ...

Mr. Childs, the lead architect of One World Trade Center, made his first design sketch on a napkin several years after the Sept. 11, 2001, attacks.

including 1 Worldwide Plaza in the Hell’s Kitchen section of Manhattan and the Deutsche Bank Center, formerly called the Time Warner Center, with its twin skyscraper towers at Columbus Circle.