Some of the biggest and most expensive transportation projects in the world have involved building bridges. Bridges are crucial links that carry cars, trucks and trains across bodies of water, mountain gorges or other roads. As a result, they are one of the most important aspects of civil engineering and are subject to intense scrutiny, especially when they collapse. Bridge collapses can be tragic events, leading to loss of life and serious property damage. That's why bridge engineers, designers and builders must always take their jobs very seriously. The best way for them to prevent these accidents is to understand why bridges collapse in the first place. Understanding bridge collapses can lead to major changes in the design, construction and safety of future building projects. The following are main reasons why bridges fall. Fire Historically, more bridges were made of wood and were much more susceptible to fire. This was particularly true of old-fashioned train bridges, where the spark created by the steel wheels and steel tracks could sometimes cause a bridge to catch fire and burn to the ground. During construction A large number of bridge accidents occur during the construction of the bridge itself. These accidents are often due to an error made by the engineers, such as a miscalculation. The bridge collapses under its own weight, and this can be deadly for the workers