when an earthquake destroys hundreds of billions of property and those mortgages get vaporized. A mortgage is house + land ("real property"), so an earthquake

when an earthquake destroys hundreds of billions of property and those mortgages get vaporized. A mortgage is house + land ("real property"), so an earthquake won't necessarily wipe out the value of the underlying asset. And, these days, due to the scarcity of land in the SFBA and high demand, the land under most homes could be worth more than the homes themselves! That said, however, if the quake were bad enough and infrastructure were ruined, that could also kill the demand and hence the land values.