A girl's dog runs off right before the largest wave of the flood and goes missing but it isn't known whether he survives or not. Even later the girl thinks she hears him barking somewhere but she doesn't manage to get to him.
The main characters mother can not leave the house due to being fat. Not a joke per se but there is no other category for this trigger, so fyi: the characters that help her out are being unnecessary cruel about it, and it also does nothing for the story but to depict fat people as lazy and a burden. Very triggering.