Many California apartments with garages and carports on the ground story that were built before the 1980s are vulnerable to collapse during an earthquake. They are known as "soft-story buildings." Here's why they're at risk.
Common weaknesses in soft-story buildings
Few walls and flimsy columns support the ground story.
During an earthquake
The first floor crumbles during an earthquake.
Fixing the problem
Adding steel frames to the ground story can strengthen the building's vulnerability to collapsing.
Sources: Structural engineer David Cocke; Federal Emergency Management Agency. Graphics reporting by Rong-Gong Lin II and Rosanna Xia.