Otto Ungar was one of the most prominent artists in Theresienstadt. He worked at the camp’s Drawing Office, producing technical drawings and reports for the Nazis, along with other artists. At night they recorded the brutal living conditions and Nazi atrocities in secret sketches, which they buried or hid inside brick walls.
When the Nazis learned that a number of their drawings had been smuggled out of the camp, they were arrested. The artists and their families were held in the camp’s prison and tortured. Ungar was sent to Auschwitz, where he perished. After the war another artist, Leo Haas, returned to Terezín and recovered the hidden art.