I've been caught up in the History Channel's "Life After People" series (www.history.com/content/life_after_people) and I think that it's something that TNE GM's will find useful.
For those of you unfamiliar with the show, it's premise is that people have suddenly gone extinct in such a way that no other life forms or man's creations were affected. In other words, no asteroid impact, nuclear war, megavolcano, or other such disasters. Each episode shows how certain parts of the world react to our sudden disappearance. There's quite a bit of vegetation reclaiming cities and buildings falling down but they do focus on the durability of materials and automated processes left unattended. The show starts at 1 day after people and goes way out to the future: centuries, millennia, even millions of years. It has a whole "Ozymandias" feel to it.
But the show doesn't just rely on speculation, it draws on real world evidence like the cities abandoned in the vicinity of Chernobyl and this island-city off the coast of Japan that was once used for coal mining. While Nature has reclaimed the former and made it look healthy, the latter looks like a war zone after 35 years of being ravaged by the sea.
Obviously the relevance to TNE will be for the events up to 70 years and for worlds up to TL-9. But there's enough there to extrapolate to higher TL worlds and non-Earth like planets. Watching what would happen to Phoenix or Las Vegas would be helpful for any desert or dry world. And the planet doesn't have to be completely devoid of people either. If the survivors are incapable of maintaining the constructs of their civilization then decrepitude is going to happen.
Definitely worth checking out.
\_/
DED