The parts of Eliezer that died was the guilt he felt and he felt that he died inside. He lost his family, his faith, and many more things. He encountered so many situations that were very hard for him. This quote is saying that Elie doesn't know if he can be the same person that he was before. He doesn't know if he can forget about the things in the past. He feels that if he is a living corpse because he has seen so much with his own eyes that were so hard to forget. Elie feels the guilt because he didn't die along with all the others he saw die. Also, he didn't let what happened destroy him on the inside, he used it as something to help other people.
While Eliezer was at the concentration camp he lost many things. Not only his dad and his shoes and clothes. Eliezer lost things that you can't physically see. He lost his warm heart and in place of that came hardness and hate. He also lost his dignity, in place of that came shame and self-pity. He lost his sanity, turning crazed and mad. There was so much that he lost that he would never get back because the things that he lost, were lost at the concentration camp and there was no turning back.
