Obviously, from this report heading, the stage was not "staked" down. Hence the collapse. Such precise reporting...
Quote:
As Sugarland prepares to stake stage, massive stage collapses
Last Updated: Saturday, August 13, 2011
0ShareINDIANAPOLIS (AP) --
Authorities say they have confirmed at least three deaths after a stage collapsed during a storm at the Indiana State Fair, where the country group Sugarland was set to perform.
About two dozen people have been reported injured in the Saturday night iincident at the fairgrounds in Indianapolis.
Strong winds caused the stage rigging for the outdoor concert to collapse, trapping and injuring concert-goers shortly before 9 p.m.
Indiana State Police did not immediately return phone messages to The Associated Press. But the Indianapolis Star and WTHR are reporting that three people have died.
They initially were reporting that four had died, but later changed their reports to three dead based on information released by authorities.
From what has been reported, they are saying a strong downburst was the cause of the Ottawa collapse, but I'm sure the official cause won't be released for a while.
"The engineering firms that design these stages incorporate ballast systems to keep the stage and rigging anchored, and some set strict guidelines for lowering the roof when winds exceed unsafe speeds".
One of the main problems was a slow response by the people in charge. A severe storm warning had been issued about 25 minutes before the collapse, but officials did not warn the crowd until a few minutes before the wind hit. People had started to leave but with a large crowd they did not have time to get to safety.
As I was searching the news about what happened at Indiana Fair State, I found the following article about a scissor lift that was collapsed by 51 mph winds in 2010. The problem seems to be how you train the people who are in charge of structures that are not designed to withstand strong winds :
All roof systems are constructed according to DIN4112 standards and are rated up to 72 Km/h [44.7 mph] wind loading. In the event of wind speeds in excess of the specified rating it is
necessary to remove the canopy and side curtains.
, "the Indiana Occupational Safety and Health Administration is investigating the contractor responsible for temporary structure, Greenfield-based Mid-America Sound Corp".
A short description of the structure is available at :
As noted in "Safety Notes" on page 2. If the truss is to be used outdoors then the whole system must be restrained against wind loading on the truss; Please refer to "Guy Wire set" sheet.
