Thanks for the link, Jack. There are references in the account to concrete walls. I'm not sure exactly how that home was built, but it sounds like the wrong kind. The best house for an earthquake is a timber-framed, wooden house. Such house wiggle in a quake. Masonry fractures and collapses.

When we experienced a 5.5 quake from many miles away, the light and dark lines in our oak floor were jiggling like anything.