With Allied troops advancing across Germany in the final days of World War II, the SS began evacuating more and more Nazi concentration camps. By emptying the camps of prisoners, the Nazis hoped to conceal from the world the atrocities they had committed.

In late April 1945, Martin Gottfried Weiss, the commandant of Dachau, received an order to evacuate the camp so that none of the inmates would fall into the hands of the approaching Allied forces. On April 26, nearly 1,800 prisoners were put on a train and around 7,000 others were forced on a march southward to the mountains. Many of the feeble and sick prisoners died from exhaustion during the march, while others were simply murdered by the SS along the way, or else died in Allied bomber attacks.

One of the prisoners who survived this "death march" from Dachau was Wolf Pakula, a Polish Jew who later immigrated to the United States.

"In Dachau, we stayed there and then they sent us on the last march -- we marched all the way almost to the Swiss border," he said. "On May the second, we got out in the woods, where we were sleeping at night and the guards were gone. I went on the road and I saw an American tank."

German guards escaped

Most of the German guards who escaped before the arrival of the US army were never found or brought to justice. By the time the Americans had come across the prisoners on the last march south of Dachau, other US soldiers had already entered the camp itself.

Reuben Lewis was another inmate at Dachau. His family were Jews from Latvia and Lithuania, and virtually all of them perished in the Holocaust. Lewis also remembers seeing the first US soldiers arrive at the camp and how most of the SS guards managed to flee before they could be captured.

"We saw scouts, American scouts coming from two different sides," he recalled. "Our camp was based on a Luftwaffe airport. And they came, and at that point the German guards dropped their guns and called out to us that we are free people, and they escaped."

Shocked at what they found

When the American soldiers finally entered Dachau, the majority of them were not prepared for what they found: thousands of emaciated corpses, littered around the camp. The Germans had run out of coal to burn the bodies, so they had been stacked in front of the crematorium and elsewhere around the camp in the last days before Dachau was liberated.

Adding further to the disturbing atmosphere was a railroad train containing 40 boxcars, each of them overflowing with decomposing human corpses -- more than 2,000 men, women and children in tattered concentration camp uniforms or completely naked. Most had suffocated or starved to death while being evacuated from the Buchenwald concentration camp to Dachau several weeks earlier.

Nearly all of the American soldiers' accounts of Dachau's liberation attempted to describe the overwhelming stench of death and sickness that permeated the camp.

Mixed in with the dead were more than 30,000 filthy and extremely malnourished surviving prisoners, crowded into a camp originally designed to house 5,000 people. Many of the inmates at Dachau were also suffering from an epidemic of typhus, or other diseases.

Hunger was another pressing issue.

"We went to the canteen, to the German canteen, and we stole food," Lewis said. "And the only thing that was piled up there was cheese ... we stuffed ourselves, and I haven't eaten cheese after that for I don't know how many years."