For me, it has to be the infamous Metallica & Guns n`Roses concert at the Olympic Stadium in Montréal in 92. For those who don`t know or remember, here`s the story
It was advertized as the major concert event of the year, the 2 biggest Hard rock / Metal acts at the time, on the same stage. The place was packed, about 55000 people in the place.
Faith No More was the opening act, didn`t see them so no comments.
Metallica was second on the bill and everything was going smoothly until, during Fade to Black (10th song of the night), James Hetfield got blasted by a pyro on stage and got seriously burned on his arm. Needless to say they stopped playing and rushed him to a hospital. Bad accident, nothing we could do about it and wasn`t the band`s fault. Was a bummer and all we could do was wait. And wait we did...
It took about 2.5 hours for GNR to come on stage. They played for about 45 minutes, total of 9 songs, until Axl told us he was done and we should get reimbursed for the night. Thank you and good night... The place just erupted in frustration. Some idiots started a riot, broke some windows and they even burnt a Police car outside. It was mayhem. My friend and I just got out of the place ASAP so we wouldn`t get caught in the action, but we could watch from afar and it wasn`t pretty. Thank God for the venue policy to not allow beer to be sold during the day otherwise it probably would have been a lot worst.
Had the chance to see both bands later on and they each still put out great shows, but on that night it was just a complete mess...