David Olère was a Jewish Polish-born French painter and sculptor best known for his explicit drawings and paintings based on his experiences as a Jewish Sonderkommando inmate at Auschwitz-Birkenau concentration camp.
He began to draw at Auschwitz-Birkenau during the last days of the camp, when the SS became less attentive. His work has an invaluable as evidence documentary: there are no photos of what happened in the gas chambers and crematoria
Below are just some of his paintings. I believe they speak for themselves.
Arrival of a Convoy
Their Last Steps
Selection for Gas Chambers
the Remains of Children
The last one hit me hard.