Lunar colonists decide to declare their independence from Earth and start flinging rocks, with a magnetic rail gun, at Cheyenne Mountain (need to knock out Space Command).

Hopefully we will have a day warning, since I think I would want to evacuate a few hundred miles in case the boy genius on the moon who is programmming the rail gun misses a decimal point.

So, it is into the truck with the animals and supplies and off on the road.

This one might not be a problem for a few years…