A man named Maximilian Kolbe volunteered to die in place of a stranger in a concentration camp.

Maximilian Kolbe was a Polish Conventual Franciscan friar. Born January 8, 1894 as Rajmund Kolbe, he was canonized as a saint by the Catholic Church in 1982 for taking a stranger’s place in the Auschwitz concentration camp. 

To the Catholic readers, this may not be a surprise, as he is the patron saint of drug addicts, political prisoners, families, journalists, prisoners, and the pro-life movement. The late Pope John Paul II even declared him "The Patron Saint of Our Difficult Century."

 During World War II, Kolbe provided shelter to refugees from Greater Poland, including more than 2,000 Jews that he hid from Nazi persecution in his friary. He was also an anti-Nazi radio host during this time. On February 17, 1941, however, he was caught and arrested by the Gestapo. 

On May 25, he was moved to Auschwitz. In July of that year, a man from Kolbe’s barracks vanished, in what was believed to be an escape attempt. In order to discourage further attempts, the deputy camp commander picked ten men from the same barracks to be starved to death in Block 13, which was notorious for torture.

One of the chosen men, named Franciszek Gajowniczek, was hysterical over the idea of never seeing his family again. Kolbe took his place. During the starvation time, Kolbe led the men in song and prayer. After an incredible three weeks, Kolbe and three others were still alive. 

They were all killed by an injection of carbolic acid. The worst part was that the man who was thought to have escaped was found drowned in the latrine. Gajowniczek survived to be liberated from Auschwitz, though, which means Kolbe’s sacrifice was still worthwhile. 

Though his sons had died, Gajowniczek’s wife had survived. He lived with her until her death in 1977. Gajowniczek himself died in 1995. 

(Source)