It's too early to assign blame for the collapse, but that's not going to stop me from trying. The biggest problem is that officials saw that there was a fast-moving line of thunderstorms approaching, a severe thunderstorm warning in place, a covered shelter adjacent to the venue, and most importantly, a break in the concert. Normally, I don't enjoy standing in the rain doing anything, and I'd assume that would work for watching stage hands set up for a band after the opening act had finished.
If I had been in charge, seeing a fast-moving line of thunderstorms that would clear the area in under an hour, I'd probably have asked those on the ground, unsheltered from the rain, to either go inside the Grandstand, the Coliseum, or under a pavilion. I would have made it clear to the crowd that the concert would start after the storms had abated. That's me - because I wouldn't want to stand in the rain, perform in the rain, generally get wet and soaked when it's 60 degrees out. Hypothermia sucks. That's all I would have done: told everyone the concert would be delayed, and hope that enough people would voluntarily evacuate the grounds so that when a mandatory evacuation would be called, there would be fewer people to move. Even without knowing that the stage would collapse, would I want to be responsible if 3,000 people (or 12,000 if the wind went sideways) were pelted with golf ball sized hail?
This is the Midwest, after all. We're used to hail storms and tornadoes, and fierce gusts of winds when they accompany violent thunderstorms. Thunderstorms in the summer with hurricane force winds? Yes... these are fairly routine occurrences. In fact, perhaps we should rate hurricane winds based on Midwestern thunderstorms. Are the winds equivalent to an EF-2 tornado or an EF-1?
So, while the news story comments are talking about how it was a freak wind gust of hurricane strength, why are people not pointing out that the stage should have been designed to withstand a strong thunderstorm, which would be a completely plausible event? This may have been a temporary venue, but perhaps we need to question whether a temporary venue poses more risks than a permanent facility. Then again, the Coliseum that was supposed to be used as a safe shelter is also the site of a propane explosion that killed 74 people in 1963. However, as stories continue to point out, stage rigging collapsing during strong thunderstorms have already happened twice this year. Just last week, I watched a Weather Channel special on the collapse of the Dallas Cowboys practice facility. It sounds eerily similar to what happened last night in Indy. Which leads me to believe that these are real concerns with real, tangible, predictable, lethal consequences which should no longer be ignored.