Scott Nacheman, an engineering VP with Thornton Tomasetti, told the state fair commission that the metal rigging structure didn’t meet requirements that it withstand wind gusts of 68 mph.
Winds reached an estimated 59 mph when the rigging collapsed onto fans awaiting a concert by the country duo Sugarland, Nacheman said. Dozens of people were also injured in the Aug. 13 collapse.
Parts of the rigging’s support system began to give way at wind gusts of 33 mph, according to the firm’s analysis.
“It no longer has the ability to support its own weight,” Nacheman said. “Once gravity had taken over there was essentially no way the structure could support itself.”
The engineering firm said the Jersey barrier ballast system used by the stage had "grossly inadequate capacity to resist both the minimum code-specified wind speed and the actual wind speed that was present at the time of the failure,” according to WTHR-TV in Indianapolis.
Even if the ballast system had provided sufficient resistance, the synthetic webbing ratchet straps and wire rope guy lines used did not have sufficient strength to resist the wind gust, even though it was actually less magnitude than code-specified requirements, WTHR reported.
The state hired Thornton Tomasetti to review the stage structure and Washington-based Witt Associates to investigate the fair’s emergency plans and response. Both firms were presenting reports to the fair commission April 12.
Witt Associates also released a report that echoed Thornton Tomasetti’s findings but looked more deeply into decision-making the night of the deadly collapse.
Indiana State Fair executive director Cindy Hoye wanted to delay the concert, according to Witt’s Kenneth Mallettebut Sugarland representatives resisted, he said. He quoted a band representative as saying, “It’s only rain; we can play.”
Hoye agreed to start show at 8:50 p.m. as Sugarland wanted, Mallette said. However, fair officials later decided to evacuate.
Because no formal protocol for delays was in place, Witt’s Charles Fisher said, there was an “ambiguity of authority” in making the call, according to the Indianapolis Star.
“Before they got to make the announcement, the structure collapsed,” Mallette said.
Sugarland quickly issued a statement after the reports were released.
“In all the back-and-forth between the lawyers, the suggestion’s been made that we’ve somehow been trying to avoid having to answer questions about last summer’s terrible tragedy. This is simply not true.
“There is no one who wants to get to the bottom of what happened more than we do, which is why we’re ready, willing, and able to give these depositions today and tomorrow. The judge has put limits on what can be discussed, but within those limits, we intend to be as honest and open as we can.
“We want all the facts to come out, not only for the sake of all the victims and their loved ones, but also so we can make sure that nothing like this ever happens again.”
The investigations weren’t intended to place blame for the collapse, Fair commission Chairman Andre Lacy said as the meeting started.
“We put ourselves willingly and publicly under the microscope in hopes of preventing a tragedy like that which happened Aug. 13,” Lacy said.
Hoye said the findings will help determine future safety policy at the fair.
“They’re extremely important for us to use as a road map to move the Indiana State Fair forward. Unfortunately and sadly, these reports can't change the past. It is our responsibility to move forward,” WTHR quoted Hoye.
Numerous lawsuits have been filed against Sugarland and companies involved with building the stage. Band members Jennifer Nettles and Kristian Bush were to begin giving depositions about the collapse in West Virginia as the reports were released.