Federal Surveillance Center K-21B

Federal Surveillance Center K-21B, located underneath an abandoned shack, is a location in the Commonwealth in Fallout 4.

Background
Federal Surveillance Center K-21B was an underground surveillance facility used by the government before the Great War; it is now north of the impact crater in the Glowing Sea. The bunker was intended to serve as an outpost for government surveillance workers, who were to continue their work after the bombs fell. However, few workers made it to the facility; a holotape recorded by an employee named Jeff Buzensky details the death of his coworker Bill Stevens, who was only a few steps away from the trap door entrance when the bomb struck after leaving to retrieve some personal effects from his vehicle. The bunker was not stocked with enough food due to budget cuts, and its inhabitants eventually died of starvation.

Layout
An armor workbench and a few nuclear waste barrels are on the porch of the shack. The shack itself contains a Novice-locked trap door in the floor next to a skeleton and Bill's suitcase. Through the trap door is the bunker comprising the three-level underground facility, with an open shaft passing through the middle. Up to three synths inhabit the interior, one of which is a synth leader.

On the lowest level is a power armor station under the stairs, as well as a trunk and an Advanced-locked safe to either side of the Novice-locked mainframe terminal. The terminal can be used to reboot the system and reactivate the elevator across the room leading back to the surface south of the shack. However, activating the elevator will also enable two hostile Protectrons, which cannot actually be disabled using the terminal.

Loot

 * Evacuation plan note and Installation K-21B key - In Bill's suitcase in the abandoned shack. The key unlocks the nearby trap door.
 * Employee 011985TP personal log holotape - On the desk near the entrance on the upper level.
 * Stealth Boy - On a desk in the eastern corner room on the middle level, in the same room as the Eat-o-tronic.
 * Two Vault-Tec lunchboxes - One is on top of the main control structure to the right of the mainframe terminal on the lowest level accessible by jumping down from the middle level, and one is on a small cart behind the power armor station on the lowest level.
 * U.S. Covert Operations Manual issue #4 - To the left of the mainframe terminal on the lowest level.
 * Partial set of power armor with fusion core - In the power armor station on the lowest level.
 * Mini Nuke - Near the power armor station on the lowest level.

Companion comments

 * When at this location, companions make comments, which are activated at the gantry overlook.

Appearances
Federal Surveillance Center K-21B only appears in Fallout 4.