Ahead of Shavuot, Yad Vashem released a photo showing Buchenwald prisoners honoring the holiday in 1945.

The Israeli Holocaust trust added of the moving image:

American Chaplain Rabbi Hershel Schaecter z”l leading the Shavuot prayer service for survivors in Buchenwald DP camp, Germany, 18 May 1945
Rabbi Israel Meir Lau, Chairman of the Yad Vashem Council (then a child) is seated in the front row.

Rabbi Lau said of Rabbi Shaechter, “He served as a chaplain by General Patton. He entered into the barracks, where we were there, crying in Yiddish, “Jews you are free!” and we didn’t believe.”