14 June 1940 : Kaleva Shootdown , an Aero Junkers Ju 52-3 / mge aircraft flying from Tallinn to Helsinki was shot down by two Soviet SB-2 bombers over the Gulf of Finland . At that time there was no war between the Soviet Union and Finland . Among the passengers were the French diplomatic couriers Paul Longuet and Frederic Marty and US courier Henry Antheil from the US embassy in Helsinki . The Soviet Union had declared an embargo on Estonia on 9 June 1940 , and the Soviet air force was ordered to prevent Estonian or Latvian air force flights to Finland or Sweden . Various theories for the shootdown have been presented , one being that the Soviet Union wanted to get hold of the diplomatic mail that was transported in the aircraft , and subsequently picked up by a Soviet submarine which was operating in the area at the time of the downing
Kaleva Shootdown
Kaleva (airplane)
List of accidents of Aero O/Y