However the most serious damage has occured when diagonal cracks appear in the walls themselves, they should be checked by an engineer immediately.
Cracks are most likely to appear at the corner of openings diagonally.
The shorter these cracks are, the less damage has occured. These will need repair but are not risky. Also check for cracks between slab and walls. These are not risky to the basic stability of the structure. The earthquake has devastated thousands of lives and rendered millions homeless.