What are some examples of irony in The Boy in the Striped Pajamas?

There are numerous examples of irony in the story. One such example comes when Bruno complains to Shmuel about being bored and alone. He resents the fact that, on his side of the fence, he's stuck with nothing to do and no-one to play with, while Shmuel has dozens of friends and gets to play for several hours a day. The irony here, of course, is that it's Bruno with plenty of free time on his hands, not Shmuel; it's the Jewish boy, the prisoner, who's stuck behind a fence.
Bruno thinks he'll soon be leaving for Berlin, and so wants to plan one last adventure with Shmuel before he goes. Sadly, it does indeed turn out to be their last adventure together but not in the way they intended. And Bruno's tragic death in the gas chamber, holding hands with his best friend Shmuel, provides additional irony. Bruno's father Ralf, in his warped Nazi imagination, thinks that by murdering Jews he's somehow protecting his people, the so-called master race. Yet when it comes down to it, he can't even protect his own son from suffering a similar fate to people he regards as racially inferior.