Structure collapse in an Israeli synagogue - work of resonance?

[Bud]

Looks like hundreds of people moving in unison may have created  favorable conditions for a resonance so the structure self-destructed?

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https://www.cnn.com/2021/05/16/middleeast/israel-bleacher-collapse/index.html

[AntiProtonBoy]

I'm betting the structure was not properly rated to for the load. If there was resonance, I'd expect the whole structure sway, but I couldn't see anything like that.

[AlbertL]

Might have been incorrect assembly; perhaps some bracing omitted?  The loading doesn't seem beyond what I'd expect bleachers to be designed for.

[Stray Electron]

I'm betting the structure was not properly rated to for the load. If there was resonance, I'd expect the whole structure sway, but I couldn't see anything like that.

  I watched the video over and over but I couldn't see any sign of the bleachers swaying but the entire crowd on it was swaying and it was so crowded that I couldn't see the bleachers themselves. I think that, based on the pictures alone, it's impossible to tell of the bleachers were swaying or not.

[Gribo]

The builders used metal wire to attach the beams to each other, no screws, no nails, no brains either. Inspectors warned about this structure 2 weeks prior, and were ignored.

[AntiProtonBoy]

Inspectors warned about this structure 2 weeks prior, and were ignored.

what a surprise