Battle of Drøbak Sound

9 April 1940, Drøbak Narrows, Oslofjord

Norwegian victory; Blücher sunk and the landing at Oslo delayed

The force sent to take Oslo on the first morning of the invasion, led by the new heavy cruiser Blücher under Rear-Admiral Oskar Kummetz and carrying the staff that was to run occupied Norway, steamed up the Oslofjord in the dark. At the Drøbak Narrows, Colonel Birger Eriksen of the Oscarsborg fortress, with no orders and no news of a war, opened fire at close range with his two 28-cm guns, built in 1893 and nicknamed Moses and Aron. Smaller guns at Kopås joined in, then two old torpedoes from the hidden battery on Nordre Kaholmen hit her. Blücher capsized and sank in the narrows; perhaps 600 to 800 men died. The rest of the force turned back and landed its troops down the fjord, and Oslo fell only that afternoon, to troops flown in. The delay let King Haakon, the government and the gold reserves get away from the capital, and Norway fought on.