Okay, I was exploring Vault 11 for the Brotherhood of Steel quest and I didn't have the key to open the place under the overseer's office so I just kept exploring.. There's a lot of traps set up in this place and in one room, I shot a mantis and the entire room exploded with gas or something - I just figured I was dead at first... But then I noticed I was in a long tunnel telling me to go towards the light, so I did.. Anyway, I guess you know what happens down there..
Here's the strange part.. After killing the robots and trying to get out of here for about 30 minutes I did some Googling and found out that that tunnel I was in was below the Overseers chair.. How the hell did I get there? I guess the game glitched when that room exploded and now I can't exit because there's no way to access the door that I was supposed to come in through....
I'm on PS3, by the way, so no console commands...