The stagelighting company I work for does truss structures and roofs for concerts and events. I have done lots of them. Safety is always a concern. If the sky looks threatening, or the wind really starts whipping, we'll crank (or motor) the roof down to a safe height and tighten all the cables holding it down. We have had to tell bands "I don't care who you are. It's not safe. We're stopping the show."
That wind must have come up awfully fast for this tragedy to occur. I'd like to think that the crew chief was doing his job, and this disaster was completely unavoidable. We have nightmares about this very kind of thing. I feel for everyone involved.