Fehlauer's Savage Tide
Sasserine is a coastal city which is spread across the edge of a bay at the mouth of three rivers and the islands within that bay.
The party later returned to Sasserine, and were there when the Change occurred. They witnessed its gradual decline, and barely escaped its destruction. As far as the characters know, what was once the city of Sasserine is now nothing but another burned-out ruin infested with monsters.
More information about old Sasserine can be found in the Savage Tide Player’s Guide.