Post-apocalyptic Worlds The bigger; the better. The smaller; the easier.

Everyone knows and loves at least one work of post-apocalyptic fiction. Whether the Earth was consumed by nuclear fire or invaded by monsters from outer space, we humans seem to have a fascination for cataclysmic disater.

It is easy for us to imagine a paradigm shifting disaster the smaller the scope is. We can imagine the downfall of a city and/or nation due to plague, war and/or natural disaster (mainly because it has already happened many times in history). We also can easily extrapolate what kind of actions and/or phenomena would be needed for human society to collapse on a global scale (the current favorites among authors seem to be nuclear war, world-wide pandemic, and ecological disaster). But once we leave Earth and settle the other planets of the system and/or galaxy, it becomes a tad bit more difficult to imagine what kind of disaster would be needed to make such a widespread civilization collapse.

So, the question stands like this: ¿What kind of disaster, be it natural or otherwise, would be needed to make a spacefaring civilization (let's keep it confined to the Solar System for the moment) collapse?

A black hole could render an entire star system uninhabitable, or even completely obliterate it.

I have that in my story that all of humanity's first colonies in the solar system are completely obliterated by a black hole entering our system.

Any sort of communications and transportation breakdown that prevents the various parts of the solar system from talking to or visiting one another would be sufficient. It's highly unlikely that all the parts of the solar system can produce all the types of goods that their citizens need (in fact many may be totally incapable of it) and the resultant isolation would result in a number of societies that are at best barely able to function.

Possible sources of this kind of problem would be energy shortages, civil war, invasion by an extra-solar system power, possibly prolonged meteor showers or cosmic storms though don't quote me on that.

A black hole would wipe out the solar system. Actually, given that black holes are generated from the wreckage of dead stars, the solar system would be long since dead, as its sun would have ceased to function.