Remember, a lot of the structures in the tristate area were not designed with quakes in mind. A 4 or 5 might feel a lot more uncomfortable if you’re standing in an unreinforced masonry building that could topple if you fart too hard.
I’ve heard a few people say this. I’m curious about where that is coming from.
Siesmographs show that looser soil produces higher amplitude waves, which is much more dangerous. Bedrock produces smaller, but more frequent waves. When you build in earthquake country, the modern goal is usually to drill pillars down to bedrock.