It was a place of the Battle of Wizna (September 7–10, 1939) during the initial stages of the German Invasion of Poland which started World War II. The Polish defense force consisted of approximately 700 soldiers and 20 officers armed with 6 pieces of heavy artillery. They held a fortified territory against a vastly larger invading force at great cost of lives, before being annihilated with no known survivors. Heavy German assault on Polish bunkers continued for three days and was successfully repelled until the early morning of September 10. The German engineers with the help of tanks and explosives managed to destroy all but two Polish bunkers. Both of them were located in the centre of Góra Strękowa, and despite having much of the crew wounded or incapacitated and most of the machine guns destroyed continued their resistance till the end. It is said that General Heinz Guderian threatened the Polish commander, Captain Władysław Raginis, that he would shoot the POWs if the remaining force did not surrender. The symbol of Polish will, Władysław Raginis, committed honorable suicide by throwing himself on a grenade. German losses are not known. In his diaries Heinz Guderian noted that 900 German soldiers were killed in action, although that number is probably underrated. It is certain, however, that the Wehrmacht lost at least 10 tanks and several other AFVs in the struggle. Afterwards, the settlement was handed over by Germany to the Soviet Union in accordance with the Molotov–Ribbentrop Pact. It was under Soviet occupation until 1941, when it passed under German occupation following the Operation Barbarossa. Wizna Jews during the Holocaust On 22 June 1941, during Operation Barbarossa, most of the houses of Wizna's 600 Jews were burned down following an aerial bombardment. Five German soldiers arrived on 24 June 1941, and local Poles killed three Jews on the same day. Jews fled the town, and local Polish collaborators searched for them in the surrounding villages and turned them over to the Germans after beating up the Jews and their Polish helpers. On 26 June, local Poles locked 20 Jews up in a smithy and a German threw in hand grenades, killing them all. Most of the town's Jews returned by early July, and dozens were killed by the Germans. The Polish mayor ordered the expulsion of the Jews, due to the lack of housing, some traveled to Łomża and some 200-240