Byline: James Gardner From left: 15 Penn Plaza and One World Trade Center As you may recall, several years ago, in the aftermath of 9/11, skyscrapers were thought to be a thing of the past. Developers, reflecting the mood of the people at large, were confident that no one would ever wish to rent floor space on one of the upper stories of a truly tall building. In the heated debate surrounding what should be built at ground zero, solicitous souls implored architects to design far lower buildings -- 45 stories at the most -- lest we seem to provoke the ire of terrorists, or tempt fate through our architectonic hubris.