24th August 1921
U.S. and Austria sign a separate peace treaty officially ending the war between the two nations. Other Allied nations concluded peace with Austria in the Treaty of Saint-Germain-en-Laye, but the U.S. did not ratify that treaty due to its refusal to join the League of Nations.
R.38-class airship (SR-2), the largest airship in the world, suffers a structural failure during flight trials and crashes into the Humber Estuary in northern England, killing 44 of its 49 crew.
