Cheap Trick is suing the organizers of the Ottawa Bluesfest and the companies responsible for building the stage, sound, and lighting rigs for $1 million in damages, 

Back on July 17th, 2011, Cheap Trick was 20 minutes into their set and had left the stage only seconds before a massive storm blew in and caved in the structure. A total of three people were injured -- including the band's bus driver. Cheap Trick's equipment was totaled. The band's corporation, Cheap Trick Touring, Inc. is seeking "$400,000 for damages to their equipment, with the rest going to costs incurred in the aftermath of the incident, including replacement instruments, labor, travel and services."

Following other stage disasters in Oklahoma, Indiana, and Belgium, on October 3rd, 2011, guitarist Rick Nielsen and manager Dave Frey appeared before congress in Washington, D.C. to seek a government solution to collapsing temporary stages.

This type of thing seems to be happening more and more. Other notable stage collapses were at a Radiohead concert last summer killing one and that Sugarland disaster at the Indiana State Fair in 2011 that killed 5. Here is amateur video of that Cheap Trick incident...