Need a hook for systems collapse? JENGA!

Monday, we are getting into Era 4: Regional Webs. I always like doing the Era Overviews on the Monday following our Friday Era Assessment, but it sometimes can feel a little flat. So last year, I started the Monday class with a game of Jenga to illustrate the concept of collapse and how it is a slow process that eventually leads to one event causing the collapse. I own a Jenga set and now am thinking of writing some causes on the blocks, there are 54 blocks so I need some help with some ideas to put on those blocks!