On the morning of August 7, 1974, 24-year-old Philippe Petit stepped onto a steel wire between the Twin Towers in lower Manhattan.

A police officer was dispatched to bring him down and observed in helpless amazement that Petit was dancing, and laughing. His feet left the wire as he bounced and resettled on it again. 

 http://www.pbs.org/wgbh/americanexperience/features/biography/newyork-tightrope/

Picture source:  https://www.google.com/#q=philippe+petit+photos