One interesting fact about the Twin Towers is that they were actually designed to withstand a possible plane crash. Another fact is that tightrope artist Philippe Petit performed an illegal tightrope walk between the two towers in 1974.
Long before the events of Sept. 11, 2001, the World Trade Center faced concerns about the possibility of a plane crashing into the building. In 1968, as the towers were being constructed, Empire State Building owner Lawrence Wien even printed a critical ad in The New York Times claiming that a commercial airliner was likely to fly into one of the extremely tall buildings. Designers actually took the potential of a plane crash into account, and the towers were built to withstand a crash from a 707 airplane, the largest commercial aircraft in existence at the time.
French daredevil Philippe Petit gained immediate fame when he completed a 45-minute tightrope walk between the Twin Towers on Aug. 7, 1974. Petit had learned of the construction of the buildings as a teenager, and he spent years preparing for the feat. With the help of friends, Petit studied the towers for months, even sneaking into the buildings dressed in different disguises in order to take measurements and stash equipment for the tightrope walk. Petit’s accomplishment actually helped raise public opinion of the then-unpopular skyscrapers among New York citizens.