AVAST! THAR BE SPOILERS AHEAD! In my current Pathfinder campaign, set in Golarion, I'm mashing up the Second Darkness Adventure Path, initially set in the seedy pirate-infested town of Riddleport, with the Freeport Trilogy, set in the seedy pirate-infested town of Freeport.
At the end of the first chapter of SD, "Shadow in the Sky," Riddleport is inundated by a tsunami. The AP doesn't make too much of it, it is kinda just "yes and it's all hard but they clean up and it's all better." I would like to run an adventure in the flooded Riddleport of the aftermath, and would specifically like something horror-oriented. So I'm looking for scenario suggestions.
The PCs are fifth level, and have a monk, a rogue, a cleric, and a ranger/druid. They're pretty buff and not nice, they're aspiring pirates and half of them are evil. I'm happy to use anything for Pathfinder, 3.5e, 3e, or even older editions. I have a lot of everything published for 3/3.5e, 2e, and 1e including most of the run of Dungeon Magazine, so I might have it already (the difficulty being rooting through all that!), or at least be able to get it at my well stocked local FLGS. I am kinda willing to consider PDF but I really like print better if I'm going to use it at the table. Even especially clever inspiration from other game systems (Cthulhu, whatnot) are welcome.
In in addition to an adventure, any resources on what I'm calling "Katrina horror" would be nice; I want to have the flooded urban environment to be a substantial part of the feel of the scenario. So you don't have to just suggest scenarios I can use straight, resources that might be helpful in running a D&D flooded-city horror adventure are welcome.
Edit: I ended up using a combination of Carrion Hill (Pathfinder module) and "The Stink" from Dungeon 105. Plus I basically reskinned all the random encounters - a "pickpocket" was a displaced person trying to swipe something, "giant roaches" were forced out by the flooding and took over a tavern, a "zealous merchant" was warning people away from his storefront with a crossbow, fearful of looters. Oh, and I exposed them all to cholera.