1926 - The American Olympic athlete, Gertrude Ederle, became the first woman to swim across the English Channel. It took her 14 hours, 39 minutes to swim the 56 kilometers from France to England. She held the record for 35 years.
1945 - The world's first atomic bomb was dropped on Hiroshima. An estimated 140,000 people were killed by the bomb and its aftermath.