Not uninsurable, but buildings are going to have to become tougher. It's happened before. Chicago's reaction to the Great Fire was simple - no more building wooden houses. Chicago went all brick. Still is, mostly. The trouble is, brick isn't earthquake resistant. Not without steel reinforcement. I live in a house built of cinder block filled with concrete reinforced with steel. A commercial builder built this as his…
This is an extreme that is not true. Bricks are harder to make earthquake resistant but it's perfectly possible to build houses that have SOME bricks in it that are also earthquake resistant. There are permutations of materials that are both more fire resistant and more earthquake resistant to the required level at a certain height of the building.