Skyscrapers are built to survive plane crashes

Modern skyscrapers are mostly air. If you ground up the Empire State Building into a fine powder, the resulting pile of dust would barely fill a fraction of the space the building occupies. This hollow nature is exactly why they don't shatter like glass when a plane hits them.

Instead of a solid stack of bricks, a skyscraper is essentially a giant steel sponge. When a massive impact severs the main support columns on one side, the building doesn't fall because it "realizes" the weight needs to go somewhere else.

This is thanks to a trick called redundancy. Engineers build the skyscraper as a "tube-within-a-tube." The outer walls act like a stiff soda can, while the inner core acts like a rigid straw. They are tied together by belt trusses—massive horizontal steel braces that look like a weightlifter’s belt cinched around the building’s waist.

When a section of the exterior is ripped away, these belts instantly reroute the gravity. The weight that used to travel down the broken columns is yanked sideways and shoved onto the healthy columns nearby. The building literally shifts its own weight mid-air to stay upright.

It gets weirder: skyscrapers are designed to be flexible, not stiff. If a building were perfectly rigid, a high-velocity impact would snap it like a dry twig. Instead, they are built to sway several feet in the wind. This elasticity allows the skeleton to absorb the kinetic energy of a crash, vibrating like a tuning fork rather than crumbling into a heap.

The goal isn't to make the building indestructible, but to prevent a "progressive collapse." This is a domino effect where the failure of one floor crushes the one below it. By using "fuse" joints, engineers ensure that a local failure stays local. The building sacrifices a few rooms to save the thousand rooms above and below them.

Even as the fire thins the steel and the wind pushes against the gash in the side, the skyscraper is actively fighting a silent war of physics. It is constantly moving its center of gravity to compensate for its new, jagged shape.

The terrifying reality is that a skyscraper can lose a significant portion of its structural support and still stand perfectly still, hiding the fact that its entire skeleton is screaming under the pressure. The building isn't just standing; it's holding its breath.