Heavy interior walls

Nonstructural walls in older buildings are often built of heavy, unreinforced masonry materials such as brick, concrete block, or hollow clay tile. These materials are advantageous for fire and sound proofing and thermal insulation, but are brittle since they do not have a grid of horizontal and vertical steel reinforcing bars embedded in them. Falling masonry in hallways and stairwells is a particular hazard for occupants attempting to exit buildings during an earthquake.