Wouldn't the not so strong old buildings have collapsed during previous quakes?
replyThey could have been further away from the epicenter of the previous ones, or the previous ones weren't strong enough to cause that specific structure to collapse, the previous ones might have weakened the structure and this one brought it down, a million different things factor into this.
replyEarthquakes aren't a perfectly repeatable occurrences you can run a regression test against.
Possibly, and then rebuilt. They rebuild houses every 20, 30 odd years anyway (according to https://www.theguardian.com/cities/2017/nov/16/japan-reusabl...), and temples too https://longnow.org/ideas/long-term-building-in-japan/.
replyMeanwhile here an 80 year old, completely unremarkable house is likely to get declared "historic" and you as the owner can't even change the windows without permission. Tearing it down would be virtually impossible.
replyIf only a 7.1 earthquake came along to cull the herd every now and then?
replySome of those old houses seem to burn mysteriously. Bad wiring, I suppose.
replyThen there was the developer who tore down a couple of houses over a weekend before the historical commission had a chance to meet and formally confer historic status on the rotting, worn out properties.