Here is a construction set which can be used for a fast and easy creation of some sewer systems.
There are two rigged elements in this set which would fit well into a horror game.
A tube which deforms and blocks the way if you tried to run through.
A tube that begins to move when you get closer and the camera view turns red.
All components are grouped, you can find the objects in the C_Set scene.
Feel free to use this set for you game project.