As people have stated previously; the twin towers were supported by a central column made of steel. Both planes went straight through the center column.
The intense heat weakened (not melted) the steel, and given that it had to support the top of the structure, it collapsed due to the weight.
As for building 7, I don't see how you find the official story to be ridiculous. The North Tower collapsed, with large chunks of debris (we're talking sections of the outer building several stories high) crashing into the building. That alone caused structural damage, and the fires that were started as a result weakened the structure in the exact same way it did to the towers.
The intense heat weakened (not melted) the steel, and given that it had to support the top of the structure, it collapsed due to the weight.
As for building 7, I don't see how you find the official story to be ridiculous. The North Tower collapsed, with large chunks of debris (we're talking sections of the outer building several stories high) crashing into the building. That alone caused structural damage, and the fires that were started as a result weakened the structure in the exact same way it did to the towers.





