Look at this image of one of the Twin Towers under the construction. Look at the core structure carefully. Under no circumstances this structure could completely collapse under the weight of a small section of the building collapsing, nor could it ever collapse due to fire.

While the exterior framed-tube (236 closely spaced perimeter columns) resisted lateral wind loads, the core worked in tandem with the exterior shell to support vertical gravity loads, allowing for the signature open, column-free floor plans.

The core columns and internal structures were protected by sprayed-on fire-resistant material and enclosed in two-inch thick gypsum board panels to maintain structural integrity during fires.

📱 ROBINMG