The accident happened in the small town of Hasselt about 50 miles from Brussels.
Video shows the PA system swaying in 50 mph winds and pouring rain and hail shortly before the structure collapsed.
In another video, fans can be seen panicking and running for cover.
Video #2 - Uploading. Coming soon.
The squall caused the Chateau Tent, where American band “Smith Westerns” was preparing to perform to collapse.
The band posted on twitter saying,
"Stage collapsed max almost got crushed by the tress, I hope Pukkelpop has insurance because all our stuff is broke."
Some 60,000 music fans were expected to turn out for the three day Pukkelpop festival that had performances on several stages throughout the festival grounds.
Reports say that four of the stages may have collapsed.
This is the second stage collapse resulting in multiple deaths in the last 5 days.
Last Saturday a stage at the Indiana State Fair in Indianapolis Indiana collapsed killing five people and injuring at least 50 others.
Related: Stage Collapses at Indiana State Fair - 5 Dead - Video
An industry insider said,
“This is way bands don’t like outside venues. It’s just too dangerous and these elaborate stage setups can be massive. On false move and it can all come tumbling down - weather is unpredictable.”
Word is slowly leaking out on the condition of those injured but it could be days before authorities know the full impact of the tragedy.
Other bands that were scheduled to perform at the festival were Good Charlotte, Fleet Foxes, Foo Fighters, Eminem, and Thirty Seconds to Mars.
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