Did an outdoor gig in Vegas on a T-shaped runway. My band was at the top of the T and above and just behind us was the biggest American flag I've ever seen. It was held up by several industrial cranes. We were told that, at the climax of this opener for a construction convention, fireworks were going to go off. I told them I was very leery about where the fireworks were placed and got the typical, "not to worry, we've done this before" crap.
This was typical, trite unimaginative crap. Anyway, we started playing Stars & Stripes Forever, Vegas chorus girls in skimpy Uncle Sam attire pranced up and down the runway, these massive fireworks started blasting up from behind the stage - between the stage and the flag - and just then wind caught the flag making it bow outward. Instead of going straight upwards, the fireworks hit the flag and arched right into the audience. It looked like an NVA attack on Khe Sanh. People scattered everywhere.
It was hilarious looking, except that there were a number of elderly in wheel chairs, as well. Ambulances had to rush in and carry some of the people off. It was one of those times where you glanced over and gave the clients one of those, "well, dumb @ss, don't look at me", looks.