I don't know what you mean by a free fall explosion. If you wonder how it could just fall in on itself I'd suggest looking at this picture of the central shafts. It's certainly not impossible that the building would collapse as it did given the situation but you're free to believe whatever you want.
Jet fuel did not melt the steel. It weakened it. Similar to if you sat on your eyeglasses and take them to be straightened/repaired. The technician will use a heat gun to soften up the metal so it bends easily.
What nonsense. Life Pro Tip... never buy a new house. Builders are hiring the cheapest labor and using the cheapest materials and then they charge you a premium because it's "new".
I don't know what you mean by a free fall explosion. If you wonder how it could just fall in on itself I'd suggest looking at this picture of the central shafts. It's certainly not impossible that the building would collapse as it did given the situation but you're free to believe whatever you want.
https://images.skyscrapercenter.com/thumbs/42958_300x415_317.jpg