Mayor is a type of Politician. Politician does not want (to) Scandal. 
you are likely to find Wheelchair in/at/on Hospital. you are likely to find Hospital in/at/on City. City is related to Government. Government is related to Bureau. 
Mayor --IsA--> Politician --NotDesires--> Scandal 
Wheelchair --AtLocation--> Hospital --AtLocation--> City <--RelatedTo--> Government <--RelatedTo--> Bureau 