How can impermanent terrain be justified?

I've been participating in the No Man's Land Heroclix tournament series for the past three months so I can get my greedy gaming hands on the new monthly maps. Each double-sided map depicts a specific Gotham City location location before and then after an earthquake strikes!

For example, from Heroclixworld.com, here are great pics of the outside of Wayne Manor before and after the earthquake:

Before...and swanky.

After...and an insurance adjuster is en route.

Each tournament game starts on the "before" side of the map. At the beginning of each team's turn, the player rolls two six-sided dice. On a total result of two or three, the earthquake hits Gotham, and the map is turned over. (All maps are lined with coordinates, so placing pieces where they belong is no big deal.)

In each of the locations, the sudden change in terrain can remove cover, create new elevations, or even trap a character! For a solo player, such a shocking twist is a welcomed event!

(I'll show you how one of these shocking twists can really affect a solo game when a certain sorcerer returns to this blog this week for a very special Valentine's Day message about love...)

Ultimately, I'd like to apply "impermanent" terrain to other solo skirmish miniatures war games, but how? Besides an earthquake, how can impermanent terrain be justified?

Any ideas?