The black youths were hanging around in the Midway area which is physically separated from the rest of the Wisconsin State fair grounds. They were only at the fair to cause trouble. Sporadic fights broke out among the animals around 6:00 PM. It finally got to the point where State Fair police swept the midway area and forced the youths off the grounds. This is where the worst of the trouble started, outside the grounds. Law enforcement outside the grounds (Different agencies due to a quirk of where the State Fair is located) were not prepared for the mass of black thugs.
So to summarize: these poor disenfransifed black youths were systemically profiled by racist
state fair personnel and called in the police to restore order
They were forced by abide by normal culturally boundaries by being asked to act like white people and retaliated by attacking and assaulting innocent white people and venting their rage