It looks like they’re actually tier 1 (they seem to be standing on a white platform), but what, if any, weight is each layer above them? I can see narrow platforms, but are they all taking most of the weight?
I’m not sure whether this was meant as an athletic or purely aesthetic display – since they’re billed as ‘acrobats’, I assumed skill was involved, so what would be the best and worst case scenario those 8-10 in the narrowest tier would be supporting?
e: was there any kind of structural support in this? I’m not finding much about it.
Here’s a Snopes article about this event at the 1980s Olympics in Moscow.
There is absolutely a structure supporting the weight of the acrobats at each level. You can clearly see two platforms. And how else are those folks leaning outward supposed to be supported if not for a central structure. They’d just fall out if they weren’t reaching back holding onto a central structure.