Part 2/8:
Both towers collapsed at a pace that led many observers to note that it resembled free fall. This raises the question of why the South Tower, although struck second and burning for a shorter period, collapsed first. Notably, calculations based on Galileo's law of falling bodies imply that the South Tower, which stood 1,362 feet tall, should have taken approximately 9.2 seconds to collapse if it were in a pure free-fall scenario.
However, the visual evidence during the collapse indicated an almost complete pulverization of the structural components. Over 200,000 tons of steel were shattered into pieces of just a few feet long, and an estimated 425,000 cubic yards of concrete was pulverized into dust, extinguishing thousands of lives almost instantly.