The struggle over the control of organized crime between the Chicago Outfit and the North Side Irish gang resulted in the infamous Saint Valentine's Day massacre, in which seven men from the North Side Irish gang were murdered in broad daylight.
Organizācija cīnījās par organizētās noziedzības kontroli ar īru bandu "North Side", kas beidzās ar septiņu īru bandas locekļu noslepkavošanu gaišā dienas laikā.