I don't believe that the band knew until afterwards either. Your aunt must have been beside herself until she heard from your cousin.My 1st cousin was at that concert. She didn't know it happened until she got home. My aunt, on the other hand, heard about it on the news before the concert had ended. No cell phones back then. As I recall, they outlawed festival seating in Cincinnati after that incident.
My niece wanted to go to the Great White concert the night they had the fire, but couldn't find anybody to go with her.
I'm sure she is glad that she didn't go.