The Pitt underground is an area in the Fallout 3 add-on The Pitt and contains The Pitt's power plant. It can be accessed from the steelyard, near a wrecked train entering an inaccessible metro tunnel. The second exit leads to Haven's courtyard in Uptown.
Both entrances are initially locked or closed. The manhole in the steelyard can be opened with the power plant key whereas the doors in the floor between the underground and Uptown can only be opened if the Lone Wanderer assists Wernher in Free Labor. If the player character does not assist Wernher, the key can still be found on the desk in his hideout and on Wernher's body if the player character kills him. Once acquiring the key to the manhole in the steelyard, the door in Uptown close to the Haven will be unlocked, but in here only the first room is accessible from Uptown. The way is blocked and can only be opened from the underground via the steelyard.
There are many trogs in the area, most appearing in groups of two or more. Close to the Steelyard entrance, two trogs can be seen cannibalizing some unfortunate person from behind some bars but they can not be accessed without console commands. Twice during the underground's linear journey, when reaching a corner with enemies ahead of the Lone Wanderer, several trogs will spawn behind the player character and again near the Uptown exit if the broken terminal is accessed.
- Factory employee ID - On the base of the switchboard channel, in the area with the two yellow factory protectrons.
- In the second large room, after going down the ramp, there are some red arrows on the ground. The arrows will lead to a broken toilet surrounded by four traffic cones, but be careful, because under each cone there is a hidden frag mine.
- The reward at the end of the traffic cone trail is just another toolbox with random items. Disarming and collecting the mines is of far more value overall.
- Turning off the floodlights will cause trogs to swarm Uptown to attack all the Pitt raiders. This will also turn Ashur hostile to the Lone Wanderer even if the player character has earlier stopped Wernher.
- There is a workbench next to the entrance from Uptown, which is the only one in The Pitt add-on.
The Pitt underground appears only in the Fallout 3 add-on The Pitt.
Sometimes the game freezes when you enter the manhole the first time from the Steelyard. If the same thing happens again and again, it can be fixed by entering from Uptown and then going back to enter from the steelyard. [verified]