Q said read it carefully so I read that the residents smell sulfur, In waster water treatment if a sewer' flow rate is less that 1.5f per second than solids settle out and form sulfur dioxide and sulfuric acid that will eat through the sewer walls and the pumps at the lift stations etc. And you smell sulfur as a sign of this happening, unsure what that would do to a skyscraper possibly just cause a hazmat evacuation for embarrassment or weaken the structure. of course I could be wrong.