I agree this is no fluke. It is very sad 5 were killed when there should have been no one killed because of incompetence, greed, ignorance, etc. If they had 10 minutes of warning and yet no one did anything about moving folks to safety, someone, whoever it may/will be, needs to be held accountable. Obviously this will cost some folks a chunk of change, and it needs to, plus I wouldn't be surprised to see criminal charges brought up against the folks who had heard the warning and had the capability to prevent this, but didn't. I'm sure there is finger pointing going on already as to who, what, why..... but the bottom line is that safety should come first and foremost at ANY venue, inside and outside.
I know this will make stage/technical folks take a hard look at the construction of their stages, hopefully, and make some changes to make sure this doesn't happen again, like guy wires among other things.
It reminds me of the tornado that hit Atlanta during the NCAA tournament a few years ago. There was a warning out, but no one did anything until the roof got ripped off.
John