One of the films produced by the senior film department at the local university last spring was a drama about a father and his two sons in a field with the sky boiling in ash on the horizon. Nothing in the title or script referred to it but the audience all knew watching it, that this was the pyroclastic flow of the Yellowstone caldera exploding. The teen son wanted to start the truck, the dad kept stopping him, in the camera you could see their hunting rifle. The tension built as you wondered if the dad was going to use the rifle on them or what... they faced the ash in the end as it kept getting thicker, their faces looking more reddened/burned as the little boy played with his wrestling action figures on the ground. Then the teen took a pose of one of the action figures, they each took a 'hero' pose as the ash came over them.
That film still haunts me.