This really shows how fast a weather event like this can take down a structure.
The extensive article in the Ottawa Citizen (http://www.ottawacitizen.com/Bluesfest+stage+collapses+storm/5116446/story.html) describes the storm's arrival and the crowd management issues. It is interesting that the local weather reports indicated a fast approaching (100 km/h) system with wind gusts up to 140 km/h. Yet the Festival director, Mark Monahan, referred to the storm as "an unexpected event." The question needs to be asked as to why the organizers didn't consider evacuating the site earlier? It was easy to see from the weather information available that the system was going to pass right over the city. This would have been an excellent opportunity to use the big video screens to announce the impending weather and request that the crowd take-cover. Event organizers should have pre-composed informational video frames and audio announcements to address this, and other emergency information.
Additional videos, interviews, and and print coverage can be found at the CTV news web site:
As mentioned in previous posts, it takes time to clear an area and secure stage canopies and towers, so there MUST be a willingness and effort on the part of the show management to pre-emptively protect the public. If one of the tall towers that were supporting the speakers were to have blown-over onto the crowd, the injuries could have been substantial. NEVER UNDERESTIMATE THE POWER OF MOTHER NATURE.
Follow-up: 2012-11-21: http://theatresafetyblog.blogspot.com/2012/11/new-reports-on-2011-ottawa-bluesfest.html