On June 22, 1941, Brest Fortress and the city were attacked by Nazi Germany on the first day of Operation Barbarossa, Germany's invasion of the Soviet Union. The fortress held out for six days. Abandoned by the Soviet army, nearly all its defenders perished. The Germans placed Brest under the administration of the "Reichskommissariat Ukraine". The remaining municipal Jewish population (about 20,000) was sequestered in the Brest ghetto established by the German authorities in December 1941 and later murdered in October 1942. Only seven Jews survived the Nazi executions. The city was liberated by the Red Army on July 28, 1944.