In All My Sons, how does Arthur Miller present family relationships in crisis?
If I were you, I would want to look at the way that the disappearance of Larry points towards severe problems within the family, especially in the way that Kate Keller reacts to the continued disappearance of her son and her firm belief that he is not dead and will return. Note what she says to Ann and Chris and how she maintains her belief in his return:
I know, dear, but don't say it's ridiculous, because the papers were full of it; I don't know about New york, but there was half a page about a man missing even longer than Larry, and he turned up from Burma.
Kate holds on to such stories and this gives her the belief that Larry cannot have died and that he is still alive. This of course is a major problem, as it means that Chris and Ann cannot proceed with their relationship because of Kate's belief. Of course, what we discover is that the reason Kate is holding on so firmly to Larry being alive is that if she were to admit that he had died, she would have to admit that her husband was guilty for sending faulty machine parts to the war and therefore guilty for the death of other pilots like Larry. The family is definitely shown to be in crisis through this.