What is a common sign of potential building failure?

Visible sagging is a significant indicator of potential building failure because it typically signifies structural issues. When a building experiences sagging, it suggests that there may be excessive loads, deteriorating materials, or problems with the foundation. This deformation can compromise the integrity of walls, roofs, and floors, making it a critical sign for inspection and immediate action. Observing sagging can alert individuals to the risk of collapse or severe damage, prompting necessary safety measures.

Bright lights inside might indicate active use or occupancy of the building but do not provide direct information about structural integrity. Strong smells could suggest issues such as gas leaks or mold but do not specifically relate to the physical stability of the structure. Unusual noises may indicate activity within the building or can be related to aging materials; however, they do not provide a definitive visual cue regarding potential failure. Therefore, visible sagging is the most telling sign that a building may be at risk.