[1] Starting in 1940, Ross had been employed by the Department of Statistics for the Jewish Council within the Łódź Ghetto during the Holocaust in occupied Poland.

[1] Daringly, working as staff photographer, Ross also documented Nazi atrocities (such as public hangings)[2] while remaining officially in the good graces of the German occupational administration.

[4] His unofficial images covered scenes from daily life, communal celebrations, children digging for scraps of food and large groups of Jews being led to deportation and being loaded into box cars.

In the fall of 1944, Ross buried his photos and negatives in a box, hoping they might survive as a historical record.

800 Jews, including Henryk Ross, were temporarily left in the ghetto in order to clean it (8 mass graves were already prepared for them).