According to CBS Boston, it was a chaotic scene inside the TD Garden during the show, with people receiving medical treatment in the seating area as well as along the concessions concourse. "There was one kid, it took four cops to take him down," one concertgoer told a WBZ TV reporter. "He was on something, I have no idea."

The Boston Globe reports that 38 people (many of which were minors) were rushed to nearby hospitals, with at least seven ambulances and a Boston EMS emergency trailer on scene, with the situation being declared a "Level 2 Mass Casualty Incident." Many of those in need of medial attention had consumed a "dangerous substance," according to an EMS worker.