Bunker

In a normal state. In a normal city. In a normal neighborhood. And in a normal family. Bad events such as this can still happen.

A gas leak from an uncharted science lab broke out. It was toxic and could kill you in an instant if you breathe it in. This 'accidental' leak was marked down in history. This fallout caused chaos and many deaths. Everyone knew it was coming, it was announced a week before the entire planet was engulfed with the toxic air. But nobody believed it would happen until it was reported from India that many people have died from the fallout.

His parents did, they believed it was real from the beginning . So the prepared by managing to register in the Happy Bunkers company. They were let in a Bunker the day the fallout reached their city. They're all safe. . . for now.