Why did irena sendler help the Jews during the holocaust?

Irena Sendler used her position as a nurse to single-handedly smuggle 2500 Jewish children and babies out of the ghetto. She was a hero and was nominated for a Nobel Peace Prize but lost to Al Gore. It's an outrage to think that Gore promoting global warming takes precedence over a hero of the Holocaust.

Irena Sendler was a social worker who organized an underground conspiracy of young women to save thousands of Jewish children from the Warsaw ghetto during World War II. After the war, instead of being honored as heroines, these women were silenced by Communist authorities in Poland. When she was well into her 80s and 90s, Irena Sendler was finally able to speak freely about her wartime work.