When the order came to annihilate the Ghetto as part of Hitler's "Final Solution" on April 19, 1943, Jewish fighters launched the Warsaw Ghetto Uprising. Despite being heavily outgunned and outnumbered, the Ghetto held out for almost a month. When the fighting ended, almost all survivors were massacred, only few managed to escape or hide. The commander of "Verbrennungs und Vernichtungskommando" ("Burning and Destruction Detachments"), Jürgen Stroop, destroyed the Ghetto so completely that even house walls did not remain. After the war, Poles did not remove the ruins, but filled them with soil and smoothed them over. This created small mounds, on which they built houses.