According to the linked WaPo story, the fights may have been planned ahead of time via Twitter. That story also gives some frightening details about the size and scope of the melee.
““There were literally mobs of 20 to 30 kids per group and there was just constant fighting...As Hodge’s family left the park, she said she saw dozens of teenagers coming toward the car, removing their shirts and yelling obscenities, racial slurs and the word ‘purge’.”
Madness. Just plain madness.
From the article, “just playing a game”. I wonder what “game” that would be?