Non-ductile concrete buildings are structures that contain brittle concrete elements (columns, beams, walls, and connections) that tend to perform poorly during earthquakes due to the limited amount of provided reinforcing steel.

There are multiple cities across the west coast that are being proactive about reducing their seismic risk. 

A soft or weak story wood-framed building is a multi-story wood structure where the first story is substantially weaker and more flexible than the stories above due to lack of walls or frames at the first floor.