In New Guinea… The Australians capture a portion of the Japanese defenses at Gona. A Japanese convoy carrying reinforcements is diverted by air attacks, but manages to land its troops along the coast to the west. General Eichelberger, sent by General MacArthur to investigate the lack of progress at Buna, decides to relieve General Harding of command of the US forces there.
In the United States… The first manmade self-sustaining chain reaction is achieved in the atomic pile at Chicago University.