Wikipedia:Selected anniversaries/December 6
December 6: Independence Day in Finland (1917), Constitution Day in Spain.
- 1768 – The first edition of the Encyclopædia Britannica (title page pictured) was published.
- 1917 – Halifax Explosion: A ship in Halifax Harbour carrying trinitrotoluene (TNT) and picric acid caught fire after a collision with another ship and exploded, devastating Halifax, Canada.
- 1922 – The Irish Free State, the first independent Irish state to be recognised by the British government, came into existence, one year to the day after the signing of the Anglo-Irish Treaty.
- 1956 – The Blood in the Water match: At the 1956 Melbourne Olympics, the Hungarian water polo team defeat the USSR, 4–0, against the background of the Hungarian Revolution.
- 1957 – Project Vanguard: An attempt to launch the first American satellite failed with an explosion on the launch pad at Cape Canaveral.
- 1989 – Twenty-five year-old Marc Lépine shot twenty-eight people at the École Polytechnique de Montréal in Montreal, Quebec, killing fourteen women before committing suicide.
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