This interested me. The roof space of a vacant 1930s house.
The fireplaces had been removed in the bedrooms and living rooms below but the chimney breast in the attic and the chimney above that externally remained in situ.The retained heavy brickwork structure was then supported (in a fashion) by custom made steel angle brackets securely fixed to the party wall. So far, so good.
However, a large part of two chimney breasts remain unsupported below those brackets. Not a satisfactory arrangement and puzzling as to why it was so designed.
I would not fancy being asleep in a bedroom with this directly overhead.