I wasn't familiar with the story of St. Maximilian Mary Kolbe until I heard it today, his feast day.
Wikipedia and other places have a lot of interesting facts about the Polish man but the part that grabbed me is that during the Second World War, he provided shelter to refugees from Poland, including 2,000 Jews whom he hid from Nazi persecution in his friary.
On 17 February 1941, he was arrested by the German Gestapo and imprisoned in the Pawiak prison. On 28 May, he was transferred to Auschwitz as prisoner #16670.
At the end of July 1941, three prisoners disappeared from the camp, prompting the deputy camp commander to pick 10 men to be starved to death in an underground bunker in order to deter further escape attempts.
When one of the selected men, Franciszek Gajowniczek, cried out, "My wife! My children!", Kolbe volunteered to take his place.
In the starvation cell, he celebrated Mass each day and sang hymns with the prisoners.
He led the other condemned men in song and prayer and encouraged them by telling them they would soon be with Mary in Heaven. Each time the guards checked on him, he was standing or kneeling in the middle of the cell and looking calmly at those who entered.
After two weeks of dehydration and starvation, only Kolbe remained alive. The guards wanted the bunker emptied and they gave Kolbe a lethal injection of carbolic acid.
He was canonized a saint in 1982 by Pope John Paul II and the man he saved by taking his place was present at the ceremony. Wow.