PHOTOS: The World's Greatest Stunts
Will Nik Wallenda add another by walking over Niagara Falls Friday?
PHOTOS: The World's Greatest Stunts
Philippe Petit, a French high wire artist, walks across a tightrope suspended between the World Trade Center's Twin Towers in New York on Aug. 7, 1974. Petit's rogue stunt was the subject of "Man on Wire," a 2008 documentary film. (Alan Welner/AP Photo)
