Organizers say a second performance by Avicii scheduled for Friday was canceled. The cause of the collapse was not immediately clear.
The video posted on YouTube shows a very enthusiastic crowd jumping up and down in sync to the beat of the music, which can create tremendous live loading on a structure. The camera finally pans down to show the gaping hole in the platform at around the 1:20 marker. Note how visibly the security staff is dressed!
More information can be found at: http://www.beatmyday.com/2012/03/03/platform-collapse-during-avicii-gig-at-globe-arena-stockholm/