 During the interwar period, in 1937–1938, Jan Zachwatowicz reconstructed part of the walls and the western part of the bridge, demolishing one of the newer buildings in the reconstruction process.However, a lack of funds delayed the barbican's planned complete reconstruction, and the 1939 invasion of Poland by Nazi Germany put the plans on hold.During World War II, particularly the Siege of Warsaw (1939) and the Warsaw Uprising of 1944, the barbican was largely destroyed, as were most of the Old Town's buildings.