Safety caution after church concert floor collapse

Thank God no deaths thus far. I was worried about just such an event a few days ago. When structures are built to hold a capacity of say 1400 people, like this church, the code inspectors are not assuming that the people are jumping up and down. Vibrations are notorious for bringing down balconies, lofts, and floors (think of stadium tragedies too) when the supports are weakened by the oscillation of the occupants jumping, stomping or dancing.

http://www.theglobeandmail.com/servlet/story/RTGAM.20080426.wchurch0426/BNStory/National/home