The Great Synagogue was destroyed by the invading Germans either in September 1939, at the very beginning of World War II (according to Polish online Virtual Shtetl), or in September 1941 (according to Pinkas haKehilot), soon after the German attack on the Soviet Union and the creation of the Łomża Ghetto for the Jews from surrounding villages and towns. Most likely the Great Synagogue was destroyed in stages, first burned down, and leveled out later.