I saw Olivia Newton-John in the Astro Dome or Astro World in Houston (I don’t remember which) in 1980—I was 12 years old then and my mom just dropped me off with another 7th grade friend. . .seems dangerous to me now and I asked my mother about that decision recently and she said everyone there was 12.
I guess trampling is unlikely at an ONJ concert.
I saw Bob Dylan there for the Hurricane Carter concert in 1975.
(Learned not to go to a place like that for a concert)
It does depend a lot on the performers and the audience. I was at the Three Tenors concert in Paris in 1998 with a crowd estimated at 200,000 surrounding the Eiffel tower. Everyone was enthralled by the music, no rushing the stage, no excessive crowd noise, no shoving, pushing or trampling. We left quickly when the concert was over to avoid the crowd in the Metro, but otherwise we didn't have to take any precautions.