The Nazis sealed the Warsaw ghetto in mid-November 1940. German-induced overcrowding and food shortages led to an extremely high mortality rate in the ghetto. Almost 30 percent of the population of Warsaw was packed into 2.4 percent of the city's area. The Germans set a food ration for Jews at just 181 calories a day. By August 1941, more than 5,000 people a month succumbed to starvation and disease.