In the winter of 1945, the Nazis tried to destroy the evidence of the Holocaust.

It was a frigid day in occupied Poland, and for all Shmuel Beller knew, it could be his last. As Russian forces advanced toward Auschwitz, Beller and other prisoners had been told by their captors that they had to leave the death camp. So he ran into one of the storage facilities and rifled through a pile of clothing—the belongings of some of the 6,000 Jews gassed each day at the camp. Finally, he found what he was looking for: a pair of leather shoes.

Beller was one of 60,000 prisoners who were forced on what is now known as the death march of Auschwitz—part of the Nazis’ mad scramble to escape Allied forces in January 1945. As Russian and American forces closed in, the Nazis attempted to dismantle the camps and hide their crimes. But nothing could obliterate the dark truth of the death camp where they’d murdered 1.1 million people.

The entrance to the German concentration camp of Auschwitz. (Credit: Bettmann Archive/Getty Images)

Over the weeks that ensued, most of the remaining inmates of Auschwitz, the largest of the Nazis’ more than 42,000 camps and incarceration facilities, were marched to other camps near and far, walking tens and sometimes even hundreds of miles. Along the way, Beller saw Nazi guards murder prisoners who tried to escape and shoot those who lagged—including women and children so exhausted from starvation and the brutal conditions they could no longer go on. As he marched on, his feet protected by the shoes he’d grabbed before leaving Auschwitz, he saw ordinary Germans standing along the road, watching the prisoners go by.

“We walked through fields of ice, snow and blizzards,” Beller later recalled as part of the Shoah Foundation oral history program devoted to preserving testimony of Holocaust victims. “Unbelievable.”

The last days of Auschwitz, which was opened by the Nazis in Oswiecim, Poland, in 1940, were marked by chaos, cowardice and an attempt to destroy what was once one of Nazi Germany’s most efficient tools in the quest to eradicate European Jews. By late 1944, as the Allied forces of World War II wrested much of occupied Europe out of Nazi hands, it had become clear that the Nazi military—once a mighty force that had invaded and occupied most of Europe after Hitler’s rise to power in 1933—was headed toward a spectacular defeat.

As the government and military began to collapse within Germany, Nazi officials in both Germany and occupied Poland began to think about their endgame. In November 1944, Heinrich Himmler, head of the SS and one of the architects of the Holocaust, issued an abrupt order to destroy the gas chambers at Auschwitz-Birkenau, the largest of Auschwitz’s three main camps. Historians disagree on why he issued the command, which was in direct opposition to a previous order by Adolf Hitler to destroy the remaining Jews in Europe.

Some of the few surviving prisoners of Auschwitz concentration camp in Poland, 1945. (Credit: Sovfoto/UIG via Getty Images)

Officials at the camp obeyed Himmler. In late 1944, they dismantled part of the gas chambers, forcing, eyewitnesses would later recall, the Sonderkommando—a group of mostly Jewish prisoners who were made to run the gas chambers—to dismantle the structures piece by piece. Then, as the Russians closed in that January, the remaining buildings were destroyed, blown up completely using dynamite. However, the ruins remained.

Then, the marches began. The remaining prisoners deemed healthy enough to march were told to assemble into columns and leave Auschwitz. About 7,000 were left behind as 60,000 marched. Nazi guards led them through the forests and fields of southern Poland on their way to Germany. The Germans called the march an “evacuation”; prisoners immediately dubbed it the “death march.”

The trek was brutal. Those who couldn’t keep up were shot or beaten by frustrated guards, and the cold, starvation and disease exacted a terrible toll on prisoners. “Anyone who dared even to bend over—who stopped even for a moment—was shot,” recalled Iba Mann, who was 19 at the time.

The Nazis’ goal wasn’t only to destroy evidence of the camp: They had plans to force the prisoners to serve as slave laborers for the Reich. Some prisoners were stuffed into train cars to complete their journey to Germany; others escaped into the sub-zero temperatures. Of those forced to walk, some died along the way, though it remains unclear how many were killed over the course of the marches.

The only people left behind in the camp were people deemed unfit for labor—those who were too ill or weak. An SS order came down to murder any prisoners who were left, and the SS killed about 700 prisoners in response. However, order at the camp was breaking down. SS officers began escaping themselves, and the strict hierarchy that had kept prisoners in line disappeared. Those officers who stayed burned documents in a last-ditch attempt to hide their crimes. Meanwhile, the prisoners who remained huddled in hospital beds and bunks and waited. A few others escaped as the remaining guards fled.

A 15-year-old Russian boy, Ivan Dudnik, being rescued from Auschwitz. (Credit: Sovfoto/UIG via Getty Images)

Then, on January 27, 1945, the Red Army reached the camp. Inside, they found prisoners covered in excrement and starving to death, children who had been used for medical experiments, and other shocking evidence of the Nazis’ crimes. At Birkenau, the guards had failed to destroy some of the storerooms where prisoners’ stolen belongings were stored before being transported back to the Reich. Among the remaining items were 7.7 tons of human hair, 370,000 men’s suits and 837,000 women’s coats and dresses.

Only 7,000 prisoners remained at the camp upon liberation, and the Red Army immediately began to help feed and care for them. Half of the surviving prisoners died of starvation, disease and exhaustion shortly after liberation; the others slowly recovered and began their lives as displaced persons.

Though the Russians had just come across the Holocaust’s deadliest camp, the liberation of Auschwitz didn’t even make front page news. A communiqué published in the New York Times on January 28, 1945, doesn’t even mention the camp, just the city; on February 3, the paper devoted two paragraphs to the “murder factory” at Oswiecim but gave few details. As World War II raced to its end, few people could even grasp the horror that was found in the camps.

Only after the true scope of the Holocaust’s horrors were known did the world begin to react to what had happened at Auschwitz. Though the Nazis fled and tried to cover up their deeds, making it impossible to ever know the complete history of their crimes, the voices of the victims and survivors live on through their testimony.

All in all, 6 million Jews perished in the Holocaust. Today, a museum and memorial at Auschwitz preserves the remnants of the Nazis’ crimes—a reminder of the many who were killed and a testament to those who survived.

HISTORY special, Auschwitz Untold, premieres Sunday, January 26 at 9/8c. Watch a preview now.