Manhole housing from the Miła Street neighborhood in the former Warsaw ghetto

Metal sewer manhole cover housing from the Miła Street neighborhood of the Warsaw ghetto in Poland. Before World War II, Warsaw was home to the second largest Jewish community in the world and a major center of Jewish life and culture, as well as the capital and largest city in Poland. Following the German invasion of Poland on September 1, 1939, the city was occupied by German soldiers and a ghetto was quickly established on October 12, 1940. The population of the 1.3 square mile ghetto swelled to 400,000 as Jews from surrounding areas were forced to move in. The food allotments issued in the ghetto were not enough to feed the population, necessitating the creation of a smuggling network that used, among other avenues, the sewers to bring in food and medicine. In the summer of 1942, approximately 265,000 Jews were taken from the ghetto to Treblinka killing center where they were murdered, and another 35,000 Jews were killed inside the ghetto. In January 1943, Schutzstaffel (SS) and police units returned to take the Jews to forced labor camps. However the remaining inhabitants were able to resist and the Germans were forced to pull out. In April, 1943, the SS and police force returned to liquidate the ghetto. Many prisoners resisted in what came to be known as the Warsaw Ghetto Uprising, while others used the sewers to hide and escape. By May 16, the Germans had crushed the uprising and left the ghetto in ruins. When the city was liberated in 1945, only 11,500 Jews were left in the city.