Pope Francis walks through the gate of the former Nazi German death camp of Auschwitz.(Credit: AP Photo/Gregorio Borgia.)
Pope Francis walks through the gate of the former Nazi German death camp of Auschwitz.(Credit: AP Photo/Gregorio Borgia.)

 

Pope Francis walks in the former Nazi German death camp of Auschwitz. (AP Photo/Czarek Sokolowski)
Pope Francis walks in the former Nazi German death camp of Auschwitz. (AP Photo/Czarek Sokolowski)

 

Pope Francis prays in front of the death wall at the former Nazi concentration camp of Auschwitz. (L'Osservatore Romano /Pool Photo via AP)
Pope Francis prays in front of the death wall at the former Nazi concentration camp of Auschwitz. (L’Osservatore Romano /Pool Photo via AP)

 

Pope Francis prays during his visit to the former Nazi German death camp of Auschwitz-Birkenau in Oswiecim, Poland, Friday, July 29, 2016. Pope Francis paid a somber visit to the Nazi German death camp of Auschwitz-Birkenau Friday, becoming the third consecutive pontiff to make the pilgrimage to the place where Adolf Hitler's forces killed more than 1 million people, most of them Jews. (Filippo Monteforte/Pool Photo via AP)
Pope Francis prays during his visit to the former Nazi German death camp of Auschwitz-Birkenau.

 

Pope Francis meets with camp survivors in the former Nazi German death camp of Auschwitz--Birkenau in Oswiecim, Poland, Friday, July 29, 2016. Pope Francis paid a somber visit to the Nazi German death camp of Auschwitz-Birkenau Friday, becoming the third consecutive pontiff to make the pilgrimage to the place where Adolf Hitler's forces killed more than 1 million people, most of them Jews. s. (L'Osservatore Romano /Pool Photo via AP)
Pope Francis meets with camp survivors in the former Nazi German death camp of Auschwitz–Birkenau (L’Osservatore Romano /Pool Photo via AP)

 

Pope Francis visits the underground prison cell of a Catholic saint, Maximilian Kolbe, at the former Nazi German death camp of Auschwitz in Oswiecim, Poland, Friday, July 29, 2016. Kolbe, a Polish Catholic friar, sacrificed his own life during the war to save the life of another man. (L'Osservatore Romano /Pool Photo via AP)
Pope Francis visits the underground prison cell of St. Maximilian Kolbe, at the former Nazi German death camp of Auschwitz  (L’Osservatore Romano /Pool Photo via AP

 

Pope Francis prays in the underground prison cell of a Catholic saint, Maximilian Kolbe, at the former Nazi German death camp of Auschwitz in Oswiecim, Poland, Friday, July 29, 2016. Kolbe, a Polish Catholic friar, sacrificed his own life during the war to save the life of another man. (L'Osservatore Romano /Pool Photo via AP)
Pope Francis prays in the underground prison cell of St Maximilian Kolbe (L’Osservatore Romano /Pool Photo via AP)

 

Pope Francis writes on the guest book at the end of his visit in the Nazi German death camp of Auschwitz in Oswiecim, Poland, Friday, July 29, 2016. Pope Francis paid a somber visit to the Nazi German death camp of Auschwitz-Birkenau Friday, becoming the third consecutive pontiff to make the pilgrimage to the place where Adolf Hitler's forces killed more than 1 million people, most of them Jews. (L'Osservatore Romano /Pool Photo via AP)
Pope Francis writes on the guest book at the end of his visit to Auschwitz. He wrote in Spanish: ‘Lord, have mercy on us! Lord, forgive us so much cruelty!’ (L’Osservatore Romano /Pool Photo via AP)

 

Pope Francis visits the Nazi German death camp of Birkenau in Oswiecim, Poland, Friday, July 29, 2016. Pope Francis paid a somber visit to the Nazi German death camp of Auschwitz-Birkenau Friday, becoming the third consecutive pontiff to make the pilgrimage to the place where Adolf Hitler's forces killed more than 1 million people, most of them Jews. (AP Photo/Alik Keplicz)
Pope Francis visits the satellite death camp of Birkenau following the railway tracks that brought trains full of Jews to be murdered (AP Photo/Alik Keplicz)

 

Pope Francis prays in front of the Memorial at the former Nazi Death Camp Auschwitz-Birkenau, in Oswiecim, Poland, Friday, July 29, 2016. Pope Francis paid a somber visit to the Nazi German death camp of Auschwitz-Birkenau Friday, becoming the third consecutive pontiff to make the pilgrimage to the place where Adolf Hitler's forces killed more than 1 million people, most of them Jews. (L'Osservatore Romano /Pool Photo via AP)
Pope Francis prays in front of the Memorial at Birkenau (L’Osservatore Romano /Pool Photo via AP)

 

Pope Francis prays in front of the Memorial at the former Nazi Death Camp Auschwitz-Birkenau, in Oswiecim, Poland, Friday, July 29, 2016. Pope Francis paid a somber visit to the Nazi German death camp of Auschwitz-Birkenau Friday, becoming the third consecutive pontiff to make the pilgrimage to the place where Adolf Hitler's forces killed more than 1 million people, most of them Jews. (L'Osservatore Romano /Pool Photo via AP)
Pope Francis prays in front of the Memorial at Birkenau (L’Osservatore Romano /Pool Photo via AP)

 

Pope Francis prays at a memorial to victims at the Birkenau Nazi death camp in Oswiecim, Poland, July 29. (CNS photo/Paul Haring) See POPE-POLAND-DEATH-CAMPS July 29, 2016.
Pope Francis prays at a memorial to victims at the Birkenau Nazi death camp in Oswiecim, Poland, July 29. (CNS photo/Paul Haring)