Have you ever seen a blacksmith knock down a sky scraper? I'm not saying steel doesn't melt. I'm saying that 10k gallons isn't enough to do it.
10k gallons is 68,000 pounds. There are 400,000,000 lbs of steel in one of the buildings. So, by your math 1 pound of jetfuel can melt approximately 6,000 pounds of steel. It doesn't work that way.
You ignored my point. You don't have to soften four hundred million lbs of steel. you only have to soften a few hundred pounds of steel. On ONE floor. The support structure. When they get soft they will bend and the overhead part of the building come down HARD, smashing into the lower floors...the building willl pancake..one floor at a time.