Out of Egypt:

"desert sunset"

No matter what happens, he must keep out of sight of the automobile. Night falls quickly in the desert - not quickly enough. A cloud of dust grows larger by the mountains; he doesn't have much time.

He crouches under a rock too small to hide him. Ten seconds more, then death by bullets.

Dust chokes him; shouts deafen him. His nerves give and he runs.

One more step, then both car and runner are swallowed in a mushroom cloud. Night falls quickly in the Nevada desert.

- written at tonight's Sanctuary microfiction workshop

Relatedly, see this article: "Twitter inspires extra-short short stories"