The bulding was undergoing a renovation.
Old building + hot work = frequent fires.
This is how Notre Dam burned. It's how the old Capitol building in Iowa burned. It's how the Yonkers building burned. If you don't like it, the answer isn't to blame a secret cabal that wants to destroy history. THE ANSWER IS TO STOP IMPORTING FUCKING INCOMPETENT IMMIGRANT CONSTRUCTION WORKERS.
It is being done on purpose because the controllers of society don't want you to start questioning why given our modern technology does the architecture, materials and construction of these old buildings seem to be far beyond anything in modernity.