I don't necessarily mean that 9/11 is the only idea for a unusual random event, but I do mean something much more catastrophic than, your daughter who was married to the prince of france has died, now you don't have as great of a relationship with france.
I read a thread that says that the game designers were forced to stop making random events that were too . . . catastrophic, because the testers hated it. But, I think something similar to 9/11 would be fitting for a real national morale crush for an entire civ. From my perspective, that was a huge event in American history, and it came from an enemy that is not sovereign to one nation, therefore you declare war on an idea and not a country, which is much more like a random event, for Civ purposes, than being attacked by an enemy country.
I also thought that a fun addition to a mod, would have something similar to Sodom and Gomorrah. Then you have the religions of each country and if there is a state religion or something that is not in ever city, it is possible to have it destroyed in a random event.
I guess, I just hope that there will be a random event that is a complete catastrophe. I mean look at Pompeii (destroyed by volcano), many Middle Eastern cities (starved by famine/swallowed by dust storm), Britain (the black plague). And in all of these cases, there is nothing or very little left in these cities.
Anyone have other random event ideas?