Footage captured by sports reporter John Hough shows players from Alton and Riverview Gardens high schools throwing down, completely ignoring de-escalation calls from game officials.
The fight, which broke out during the game's third quarter, when Alton was leading 64 — 43, ultimately spilled into the nearby stands. At one point, a referee is knocked to the ground and nearly trampled by players.
"Stay in your seats," the game announcer can be heard saying as the brawl moves to the stands. "All kids stay in your seats. Ladies and gentlemen, do not get involved. Do not get involved."
The brawl was eventually squashed after several school officials and Madison County Sheriff's deputies managed to pull the players away from each other, according to the St. Louis Dispatch, which noted that tempers initially flared during halftime as players walked toward their respective locker rooms.
Riverview Gardens coach Milton Stith told the publication that officials believed the halftime disturbance had been settled prior to the start of the third quarter.
"It was a heated competition, and tempers flared," Stith told the Dispatch. "What I will say is that the Alton program is first class, their athletic director is first class, and they have my apology if anything happened that we could have prevented, and I take full blame for it."
Though it's unclear what exactly triggered the fight, the Telegraph reported that it broke out after two technical fouls were called on a player for the Riverview team.
The remainder of the game was suspended, and both teams were handed a forfeited loss. As added punishment, because both teams had all their players involved in the fracas, their Saturday games were also forfeited.
Further disciplinary action may follow once both the Riverview Gardens School District and the Alton School District conclude their investigations regarding the incident.