Final answer:
Thermal stress, mechanical load, corrosion, and design flaws can lead to structural failure.
Step-by-step explanation:
The primary cause of a structural failure can be attributed to a variety of factors such as thermal stress, mechanical load, corrosion, and design flaws. For example, objects made of different materials expand and contract at different rates when exposed to temperature changes, leading to stress and potentially causing failure. Additionally, excessive mechanical load or inadequate support systems can also result in structural failure. Corrosion can weaken the structural integrity of materials, making them more prone to failure.