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.
I don't think that your reasoning fully grasps how flash floods work. Even with "proper drainage" situations can materialize in the millions of differing landscapes. With ground saturation at 100% and creeks and river systems at max capacity, the water has no where else to go in many places, like flood plains, watersheds, dips in the road, etc. We can and should learn from this horrific tragedy, but a few more drainage ponds is the equivalent of Trump's "just rake the woods" comment.
In this particular case you are wrong. It is the weather. It has been raining hard for three days straight in some of these places. It is climate change and the weather. Infrastructure is definitely an issue but not the reason.
They are one in the same. The hydra of capitalism.