By any measure, the Warsaw Ghetto was hell on earth. An urban prison zone in the middle of German-occupied Warsaw, after November 1940 the ghetto was enclosed by a ten-foot high wall that was topped with barbed wire and tightly guarded. German authorities packed over 400,000 Jews of all ages into an area of just 1.3 square miles, with an average of 7.2 persons living in each room. Conditions were miserable: inadequate food, no sanitation, little heat. By mid-1942, 83,000 Jews had died of starvation or disease. Of those who managed to survive, the German authorities deported almost three hundred thousand of them to the Treblinka killing center to be gassed.