Expert explains how collapse happened

INDIANAPOLIS (WISH) - While Saturday night will be remembered as the night the stage at the Indiana State Fair collapsed -- brutally killing and injuring those trapped underneath – it was actually the lighting grid that fell

The grid that collapsed was built by a local company, Mid-America Sound Corporation. There are a lot of questions about how and why the grid and roof collapsed.

Chuck Gilespie has been a lighting designer for over 30 years, working closely with companies like Mid-America Sound. 24-Hour News 8 asked him to give an expert opinion on the lighting grid and its collapse.

Looking at video shot on a cell phone by a concertgoer Gilespie pinpointed the moment he thought the crew would begin feeling nervous – when wind began blowing the backdrops in a particular way.

The roof became a sail.

"When that wind comes up, the reason it blew out into the crowd is because that circle thing in the back and those big black drops back there became a sail," Gilespie said.

Once that started, Gilespie says the entire structure became unstable.

"Then in the video you see the PA towers start rocking back and forth side to side which now with winds 70 mph these aren't stable and they are causing these tower legs to become unstable,” he explained. “Even though they are bound and the bounding did their job, Mid-America did the best job in the world because if that would have not been there all these people could have been killed."

If that had been the case the structure would have fallen forward instead of to the side as designed.

Ballasts weighing 4,200 pound lie on the ground as weight. The guide wire is connected to that. The guide wires holding them helped it fall.

"It saved them," Gilespie said.

He says it was constructed properly from what he saw and added, “Mid-America is the best at what they do."

Gilespie and others say they could have "dropped the top," lowering the roof, but that would have taken time they no longer had.

"It would take 30-40 minutes to do this procedure but it would have saved lives," Gilespie said.

He says in his business they would rather be killed than anybody in the audience. Some of those injured were sitting in the VIP section. That is the same section where families of the employees who erected the lighting grid sit.

Mid-America has no safety violations in the last year and a half with the Indiana Occupational Safety and Health Administration, or IOSHA. Owner Kerry Darrenkamp issued a statement through a spokesperson: "This is a devastating tragedy and we want to express our sympathy to the families of those who were killed or injured last night at the State Fair. We have already started an independent internal investigation to understand, to the best of our ability, what happened."

The owner plans to attend the memorial service planned for Monday morning.