What are two examples of how the SS took their humanity from them, whether it be in their actions, thoughts, or words.

Eliezer is transferred without his father to the building unit, where he has to drag blocks of stone around, and he learns that a selection (exam for assigning people to the crematory) is planned for that day. The head of Eliezer's block gives some helpful advice: run as fast as possible in front of the SS doctors, and don't be afraid. When Dr. Mengele appears, all the prisoners march in front of him as he writes down the numbers of those to be cremated.