These earthquake standards are updated frequently. Kumamoto earthquake mentioned in the other comment is a typical example. Nowadays many believe Level-3 is a m

These earthquake standards are updated frequently. Kumamoto earthquake mentioned in the other comment is a typical example. Nowadays many believe Level-3 is a must(耐震強度3. I don't know about the U.S. equivalent. Do they even have one?). I don't know about your wife's case. Some people believe earthquakes are like the lottery (and there are a few people who believe it's a god's will. Like Shintaro Ishihara after the 3.11 earthquake).