So I have a tunnel that leads into a lake useing the hoth tunnel exit (the exit is partially underwater). After i tested it there was a huge chuck of terrain missing all around the exit (only in game, not in zero editor). Tried moving the hole tunnel system over and the hole reappeared, then i tried placing rocks to plug the hole up. Figures what happened next, the hole for some reason then decides to grow outward even more making the rocks pointless.
Oddly enough the hole stops exactly at the height of the water.
Its really annoying because this totally ruins the secret escape tunnel i was trying to make.

Is there some kind of glitch with terrain cutters and water?? Does anyone know anything about this, or am I alone here?

Okay I found out that the garbage disposal object was causing this glitch, problem solved!