March 12, 1940

1940Winter War: Finland signs the Moscow Peace Treaty with the Soviet Union, ceding almost all of Finnish Karelia.^[†]

The Winter War was a war between the Soviet Union and Finland. It began with a Soviet invasion of Finland on 30 November 1939, three months after the outbreak of World War II, and ended three and a half months later with the Moscow Peace Treaty on 13 March 1940. Despite superior military strength, especially in tanks and aircraft, the Soviet Union suffered severe losses and initially made little headway. The League of Nations deemed the attack illegal and expelled the Soviet Union from its organization.

1940The most destructive train accident in Finnish history kills 39 and injures 69 people in Turenki, Janakkala.^[†]

The Turenki rail accident occurred on 12 March 1940, at 05:28 local time near Turenki, Finland, and remains the worst rail accident in Finnish history. A troop train carrying soldiers of the 71st Supply Company and horses south from Loimaa to Viipuri collided with a northbound freight train. The two trains were travelling at 40 km/h and 25–30 km/h respectively at the time of collision. The death toll was particularly high due to many troop carriages being crushed; the carriages had initially been located at the rear of the train but were moved to the front just behind the locomotive at Toijala as the train changed direction. Rescue operations were also delayed.