WW2 War Diary for Thursday, September 21, 1939:
Artillery bombardment of key points in Warsaw greatly intensified.
Romania: Prime Minister Calinescu shot dead by fascists of the Iron Guard. Assassins captured and publicly executed.
Luxembourg: Radio Luxembourg closes down.
Britain: Government Blue Book published: prewar diplomatic documents.
Poland: The Heydrich Plan: 600,000 Jews from Danzig and Western Poland to be transported to central Poland and concentrated in urban ghettos.