That's nothing!
I had one of these spawn inside of a Rescue Mission. And when you go into it in there, you insta-fail AND kill the Survivor. ARGH!
The best part is that half the time when you go through the door, you can't go back up! The door, instead of being a door up, is another door down! I got down to Ocean Caves 6 before I realized what was happening...
Warp gates there are bugged too. You can't go into them. They'll only work if you directly teleport via the region map.