Most buildings in the ancient city of Bam were sun-dried brick masonry (clay and mud bricks) constructions with extremely poor earthquake resistance.

This slide presents the collapse state of earthquake-stricken population houses based on the cross-sectional study. I hope you have seen the slide 20 in part 5. In spite of the mentioned selection bias, as it is expected, the total collapse proportion of old style buildings was higher than modern style ones.