> They were building simple fairly short structures that can only really kill you if the roof hits you on its way down and gave a whole lot of warning before that happened.

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.