July 28, 1970: The day after a Grant Park riot occurred when a crowd of 35,000 to 50,000 waiting for a concert by Sly and the Family Stone reacted violently as the concert is delayed and ultimately cancelled, Mayor Richard J. Daley orders that all rock concerts planned by the Chicago Park District Board be cancelled. The mayor calls the fighting “A riot, a brawl, and mob action.” [Chicago Tribune, July 29, 1970] He continues, “There were a lot of liquor and wine bottles thrown at the policemen. I believe the young people who attend these concerts should assume some responsibility for policing themselves.” At least 162 persons are injured in the turmoil and hundreds of windows are broken all along Michigan Avenue opposite Grant Park as well as on some side streets between Michigan and State Streets. Damage to police vehicles is estimated at $10,000 with one car destroyed by fire. As the mayor reacts, three men and two women are arrested near the Grant Park band shell after a report that the performance venue will be set on fire. Police search the truck belonging to Mike Patrick of Brommel, Pennsylvania and find a five-gallon can of gasoline and one-fourth pound of marijuana, almost never a good combination.