SPOILER. The wife/mother's fate
SPOILERS: You'd have to have a heart of stone if you didn't feel something in this scene.
The mother/wife has despaired of living in a post-disaster world that's not worth living in. She has long wanted to kill her own son and then herself, except for the resistance of her husband who wants to go on living. So she commits suicide via hypothermia by walking out into the dark, freezing, stormy night wearing only a sweatshirt and jeans. Her husband is unwilling to imprison his own beloved wife and so is helpless to do anything as he has to watch her walk out into the storming night, never to be seen again.
All he has left is his flesh-and-blood, his own son, and his memories of his wife before the planetary-wide disaster.
It's another heartbreaking scene as the husband slowly pushes his gold wedding ring off the bridge into the chasm below because he knows that he must literally bury his memories of his loved wife before it emotionally crushes him