1917 – Halifax Explosion: A munitions explosion near Halifax, Nova Scotia kills more than 1,900 people in the largest artificial explosion up to that time.
1917 – World War I: is the first American destroyer to be sunk by enemy action when it is torpedoed by German submarine .
1941 – World War II: The United Kingdom and Canada declare war on Finland in support of the Soviet Union during the Continuation War. Camp X opens in Canada to begin training Allied Secret Agents for the War.