On April 20, 1945, just days after having been liberated, prisoners from the Bergen-Belsen concentration camp were recorded in a history-making performance. The small group of survivors sang a rendition of the Hatikvah, Israel’s national anthem, in a moving moment that has been saved for history.

This week marks the 69th anniversary of the liberation of Bergen-Belsen, one of the most violent and fatal Nazi camps. Watch the video above in commemoration.