Bogdan Bartnikowski recalls occasionally asking older inmates, out of innocence or desperation, when he would be released from Auschwitz. He recalls, too, the answer that inevitably came back.

"You want to be free?" they would tell Bartnikowski, who was 12 at the time. After a mirthless laugh, they would point to the chimneys. "This is how you get out. There is no other way out."

Bartnikowski, now 87, recounted his story Friday during German Chancellor Angela Merkel's visit to the Auschwitz-Birkenau complex in Poland. The visit, Merkel's first official tour of the notorious Nazi concentration camp since she took office 14 years ago, marks just the third time a German leader has visited to the standing symbol of the Holocaust — and the first in about 25 years.

During her visit, Merkel announced that Germany is giving 60 million euros (about $66 million) to the Auschwitz-Birkenau Foundation, which marked its 10th anniversary on Friday. The gift doubles what Germany, already the foundation's biggest financial supporter, had previously donated.

Addressing the media after Bartnikowski and Polish Prime Minister Mateusz Morawiecki, who both accompanied her on a tour of the complex, Merkel explained why it is no mere happenstance that Germany has offered so much financial support.

"To stand here and speak to you today as Germany's chancellor is anything but easy for me," she said Friday. "I feel a deep sense of shame for the barbaric crimes that were here committed by Germans — crimes that are unfathomable."

More than 1.1 million people — mostly Jews, but also Poles, Roma and prisoners of war — were murdered at Auschwitz from its founding in 1940 to its liberation by Soviet soldiers in 1945. Most were killed and burned on the premises on an industrial scale, using a series of gas chambers and crematoria — the same chimneys the older inmates pointed out to Bartnikowski.

"Nothing can reverse the unprecedented crimes committed here," Merkel added. "These crimes are and will remain part of German history, and this history must be told over and over again."

Though Friday represented Merkel's first official visit to Auschwitz, the chancellor has visited other major Holocaust remembrance sites during her time in office. Together with President Barack Obama and Holocaust survivor Elie Wiesel, she toured the Buchenwald concentration camp in 2009, and she has made several visits to Yad Vashem, the world Holocaust remembrance center in Israel.

In 2014 she received that country's highest civilian honor, "for her unwavering commitment to Israel's security and the fight against antisemitism and racism in particular through education."

During her address Friday, she drew a clear line from Auschwitz to the present political situation in Germany, which has recently seen an alarming rise in anti-Semitic violence. Hate crimes targeting Jews last year leaped by nearly 20% over the year before, according to German Interior Minister Horst Seehofer.

"I've seen people spitting out in front of me because I was wearing a kippa. People shouting at me, 'Jew,' in the middle of the streets, in the center of the city," a young Jewish LGBTQ activist told NPR's Daniel Estrin earlier this year. "And if I tell people about things I experience, they say, 'What? This happened to you? I didn't even know that there is anti-Semitism today in Germany.' "

Merkel noted that she was well aware of the distressing shift in Germany.

"We are witnessing and experiencing an attack on the fundamental values of liberal democracy and a very dangerous historical revisionism that serves a hostility that is directed at specific groups," she said. "We are focusing our attention especially on anti-Semitism, which poses a threat to Jewish life in Germany, Europe and beyond."

"Because," Merkel added, referring to the great Italian Jewish writer and Auschwitz survivor, "it is as Primo Levi once said: 'It happened, therefore it can happen again.' "