The fallen skybridge is a broken walkway hanging from a ruined skyscraper overlooking the elevated highway. The surrounding area is a tangle of pathways allowing passage between many nearby locations, including Hub 360, one of the tallest buildings in Boston.
Access to the area may be achieved by heading south along the narrow alley across the street from the Water Street apartments to reach a set of two fire escapes; the escapes lead to a button-activated elevator on the roof which ascends to the skybridge. Alternatively, one may climb various ramps or piles of rubble in and south of the Theater District to reach the lower section of the elevated highway, then proceed north along the highway towards the Financial District. The upper section of the highway may be accessed via a collapsed section near the skybridge.
It is possible to jump from the skybridge directly into Goodneighbor. There will be a loading screen about halfway down the fall, but when arriving in Goodneighbor, the player character will be in the same position as they would be when arriving through the normal entrance, and will take no fall damage.
The fallen skybridge appears only in Fallout 4.