I think the video of the collapse must be one of the most watched today in Youtube.
The reason was a strong gust of wind that pushed the stage over just after opening act Sara Bareilles had finished.
The governor of Indiana said what happened was a sad accident that no one could have anticipated.
Investigators are trying to figure out the cause of the collapse, although they know the wind played a big part on it.
The country pop duo Sugarland is OK and they are asking for prayers from fans for the people who was involved in the deadly accident.
Here is the video of the stage collapse.