Reuters/Mark Makela
On Sunday night and early Monday morning, crowds flipped over a car, set another vehicle on fire, took down and climbed light poles, smashed windows, scaled City Hall with a keg, and littered streets with beer cans and other debris. The Philadelphia Inquirer also reports that between "Everything is free" chants, several fans looted a gas station.
Philadelphia has now started cleaning up. Photos on social media show some of the morning-after mess.