On June 9, 1924, George Mallory and his partner, Andrew Irvine were last seen on their trek to the peak of Mt. Everest. He was very close to the summit, and then he disappeared. It was on this date in 1999, (75 years later) that his body was found. Unfortunately, it is still not known if he and his partner were the first to reach the summit. It will probably never be known.
More info:
http://en.m.wikipedia.org/wiki/George_Mallory
http://malloryexpedition.com/george.htm
http://www.nytimes.com/1999/05/05/world/a-body-on-mt-everest-a-mystery-half-solved.html
