I bumped the "bridge" section of District 10 this morning. While I was standing there ruminating over the possibilities of getting across the broken bridge, I noticed that all you would have to do is crawl on top of the encircling wall which happens to connect to the normal play area.
Some preliminary testing of my own revealed an invisible ceiling that is low enough to be problematic, but I have heard that certain glitchers can break these barriers! (*cough* Tepec *cough*)
I humbly request Black Ops to pool their skills and brains to attempt access to this building! Can it be done?
For what its worth, bumping the district removes a small section of street just past the detonator clue item. There was also an open room in the center with two medkits in it... I can't recall if that was open before or not. Can't check right now as I am vidcapping Data Hive in theater mode.