During WW II, Irena Sendler, got permission to work tn the Warsaw Ghetto, as a Plumbing/Sewer specialist. She had an ulterior motive:
She KNEW what the Nazi's plans were for the Jews, (being German). Irena smuggled infants out in the bottom of her tool box she carried, and she carried in the back of her truck a burlap sack, (for larger kids). She also had a dog in the back that she trained to bark when the Nazi soldiers let her in and out of the ghetto. The soldiers of course wanted nothing to do with the dog, and the barking covered the kids/infants noises.
Over the course of time, she managed to smuggle out and save 2,500 kids/infants. She was caught, and the Nazis broke both her legs and arms, and they beat her severely.
Irena kept a record of the names of all the kids she smuggled out, and put them in a glass jar, buried under a tree in her back yard. After the war, she tried to locate any parents that may have survived in order to reunite the families. Most of course had been gassed in the concentration camps. For the children without parents she helped find families to foster or adopt the children.