Used to live in an earthquake zone right in front of the ocean, so tsunamis were always a risk.
So I kept a bug off bag with water, clothes, blanket, cereal bars, lights and a battery pack ready to go by my bike.
I did use it once and skipped all over the traffic going to the shelter. Fortunately the water didn't rise enough to be a threat, but I thanks to the peace of mind the bag brought, I didn't even stress during the evacuation
I think the narration was great, the children just appear at the very beginning of the book