9 minute video, article in Rolling Stone...
http://www.rollingstone.com/rockdaily/index.php/2009/08/03/one-killed-15-injured-after-storm-causes-stage-collapse-at-country-music-festival/
The video source is CISN FM, and as the "CISNMike" Youtube poster says, sharing this helps to "illustrate how quickly things happened and how devestating the event was". Wow, reasonably calm until 1:20 then HOLY CRAP!
http://www.youtube.com/watch?v=LR_yq3mB0bM
omg compare 1:19 to 2:43 -- the stage before and after. 4:50 is a side view that helps makes sense of how the collapse happened.
*thankfully, the collapse itself was not captured in this video. Would be hard to watch for sure.