“Maybe someone would come too close to someone else and they would get banged into, but that was about it,” says guitarist Scott Ian, whose band Anthrax was heavily influenced by New York hardcore shows he attended at the iconic venue CBGB's.

Many in the crowds were also musicians, so there was an awareness of when rowdy audiences became potentially dangerous. Bands like Agnostic Front, Cro-Mags and Murphy’s Law intently policed their own shows. Yet, from the start, there was a clear community code of conduct. Ironically, the mosh (or circle) pit surfaced in the early 1980s during the New York hardcore movement, which featured more than a dozen bands far more violent than Travis Scott. Energetic mosh pit-loving fans were in close proximity to kids who may just have wanted to stand and watch the show, creating the potential for unprepared fans to be swept away in the wave and trampled. The 50,000 attendees at Astroworld were able to get as close to the stage as possible by slipping through cracks, muscling their way to the front and surging forward as far as possible.

The more bodies in the pit, the more momentum there is as the circle grows and rotates, causing formations that, from above, resemble tornados. Within the heaving mass, dancers are shoved back and forth between moshers on both sides of them, so they careen through the pit as it spirals. A mosh pit, in its strictest definition, is composed of a group of aggressive “dancers” packed together in concentric circles that rotate around one another.

Power metal mosh pit