Why did the Twin Towers and Twin Towers collapse in the 9 1 1 incident?

The main reason is the fire caused by the plane hitting the Twin Towers. Even if the two towers of the Twin Towers were hit by planes at high speed, the whole building could not be destroyed. The culprit was the explosion caused by the plane collision, which caused a fire. The plane itself carried a lot of gasoline, which fueled the fire. Many decoration materials and office supplies of the Twin Towers are flammable, and the fire spread quite quickly.

The high temperature caused by the fire softened the main steel structure of the twin towers, and because of the excessive weight of the whole building, the foundation of the building began to be unstable and constantly shaking. The floor hit by the plane softened first, and the superstructure fell down like a domino, and the impact continued to accumulate, and the whole building collapsed downward.

Extended data

In the steel scrap inspection of the twin towers after the accident, although some protective coatings were found on the steel surface, a complete fireproof coating could not be found. This shows that the strong airflow formed during the impact will blow away the refractories on the steel. Once the fireproof material can't completely wrap the steel, it will lose its fireproof effect.

The knowledge of fireproof materials is simple, and it is easy to spray on the loose rust of steel structure. If fireproof materials can be sprayed and there is no dead angle maintenance, the Twin Towers can last longer before they collapse and strive for more escape time. This is another tragedy with inadequate details.