If a wall is built of soft or hollow bricks, then in the event of an earthquake (a fall or blow), the structure will crack (a compression fracture, often a devastating event for an elderly person).
萬一由稀疏空洞磚塊砌成的房子，不幸又碰上大地震（跌倒或外力撞擊），就會造成老人家最怕的「壓迫性骨折」。