In all, the Nazi regime murdered 6 million Jews from all over Europe, annihilating two-thirds of Europe's Jews and one-third of all Jews worldwide. In 2005, the United Nations designated Jan. 27 as International Holocaust Remembrance Day.

Silence pervades the site of Auschwitz-Birkenau today. Sometimes the only sounds are the soft footsteps of visitors, people who come from all over the world to mourn and to learn, and the voices of their guides speaking in hushed tones into microphones trying to explain the ungraspable.

This International Holocaust Remembrance Day marks the 80th anniversary of the liberation of Auschwitz-Birkenau, the Nazi labor and extermination camp where 1.1 million people were murdered. SS chief Heinrich Himmler was the mastermind of what’s known as the “final solution” the deliberate and systematic plan for the mass murder of the Jewish people

The Illinois Holocaust Museum celebrated the 80th anniversary of the Auschwitz Concentration Camp liberation with Holocaust survivor Manfred Goldberg, who is now one of a dwindling number of survivors still alive.

Silence pervades the site of Auschwitz-Birkenau today. It can feel that time has stood still at the place where Nazi German forces killed 1.1 million people, most of them Jews. There are the barracks which housed prisoners,

In a solemn memorial, survivors and world leaders gathered at the Auschwitz concentration camp in Poland to mark the 80th anniversary of its liberation. NBC News' Jesse Kirsch reports.