So, you don't believe roofs were invented until very recent times? The only building I've ever been in where roof collapse couldn't be fatal is my neighbor's chicken coop.
> Castles and cathedrals and city walls and the like don't fall down unless you intentionally ignore or obfuscate a ton of cracking a slumping and things moving, etc, etc.
Easily disproven. Here's one refutation:
https://en.wikipedia.org/wiki/Erfurt_latrine_disaster
Seriously: your lack of knowledge about historical architecture is impressive.
A barn is a lot more forgiving than a tilt up Walmart. Castles don't pancake like the Surfside Condos (which gave a ton of warning BTW). I think it speaks volumes that your example is a rotted floor overloaded beyond it's capacity. This stuff isn't rocket science except in the rare cases when it is. Anyone trying to portray it as such is doing a disservice to society.
There are many failure modes other than gradually cracking and eventually failing. Even in that case, by the time you notice such cracking, the cost of repair - if it can be repaired - is dramatically higher, and has tons of effects.