The Boy in the Striped Pajamas who is to blame for Brunos and shmuels death?

To say this is a complicated question is understating it. Bruno and Shmuel spend their last afternoon together inside the fence, with Bruno dressed in striped pajamas. He has planned to help Shmuel find Shmuel's father when they are herded with a group into a gas chamber. Although the boys assume, they are inside where they are out of the rain, they are, in fact, about to die. One of the last images the reader has is of the boys holding hands, firmly convinced they will not let go. Bruno's father obviously is commandant of the camp and is therefore at some level responsible. The Nazis who envisioned the Holocaust are also responsible.