This may not seem like it is related to Niagara Falls, but this story from UPI reports that apparently a base jumper tried to jump off the Empire State Building. He was arrested before he could jump. It turns out that he previously jumped off the Skylon Tower.
Last August I asked Dave Gillies, Director of Sales for Skylon Tower, if base jumping was a problem. He said it wasn’t since the observation deck was covered. I guess this guy managed to jump before they covered it…