The Detroit police department at the time was 93% white,[2][3] of whom 45% working in black neighborhoods were considered to be "extremely anti-Negro" and an additional 34% were "prejudiced".[4] The riot began after police raided a black-owned business that hosted a "blind pig" or illegal bar, during a party to celebrate the safe return of two black Vietnam War veterans.[5] Police had expected a small number of patrons; however, there were 85 or more patrons inside.