The ghetto had been formed in November 1944 when 70,000 Jews were forced into a 0.1 square mile (0.26 square kilometre) zone with no means of escape. Surrounded by a high wire fence, the ghetto was totally cut off from the outside world, with no food allowed in, rubbish and waste were not collected and the dead simply lay on the streets. Unsurprisingly, diseases such as typhoid spread quickly.
Raoul Wallenberg decided to act.
Wallenberg knew that the only person who could prevent the massacre was General Gerhard Schmidhuber, the commander of German forces in Hungary, so he sent him a letter explaining that the general would be held personally responsible for the massacre and that he would be hanged as a war criminal when the war was over.
The general, knowing that the Germans were losing the war, relented and the massacre was stopped at the last minute. The lives of 70,000 people were saved.