The Twin Towers, part of New York City's World Trade Center, were destroyed in the September 11, 2001, terrorist attacks. Hijacked planes struck both towers, leading to their collapse due to structural damage and intense fires.

Timeline of Events

On that morning, American Airlines Flight 11 hit the North Tower (WTC 1) at 8:46 a.m., carving a massive hole and igniting fires across multiple floors.

United Airlines Flight 175 slammed into the South Tower (WTC 2) at 9:03 a.m., just 17 minutes later, with similar devastating impact.

The South Tower collapsed first at 9:59 a.m., after burning for 56 minutes, followed by the North Tower at 10:28 a.m., 1 hour and 42 minutes post-impact.

Why They Collapsed

The planes' impacts severed core and exterior columns, dislodging fireproofing insulation from steel beams.

Jet fuel sparked infernos fueled by office contents, heating steel trusses to over 1,000°C, causing floors to sag and pull inward on perimeter columns.

This triggered a progressive failure: upper floors pancaked downward, overwhelming the structure below in a chain reaction, with debris falling at near-free-fall speed for parts of the descent.

Casualties and Aftermath

Nearly 2,800 people died in the towers, including occupants, visitors, and 403 first responders, marking the deadliest terrorist attack on U.S. soil.

The collapses generated massive dust clouds, complicating rescue efforts and exposing survivors to health risks that persist today.

Over 3,000 total deaths occurred across the 9/11 attacks, reshaping global security and leading to NIST's multi-year investigation confirming fire- induced failure.

Engineering Insights

The towers' innovative tube-frame design stood for decades against winds and prior attacks, but lacked redundancy against combined impact and fire.

NIST reports emphasize that dislodged fireproofing was key—no steel-framed high-rise had collapsed from fire alone before.

Debates persist in forums like Reddit, where engineers explain why tops didn't shear off: dynamic loads from falling mass exceeded any intact section's capacity.

Ongoing Discussions

> "It took years to build and under two hours to destroy—jet fuel and gravity did the rest." (Engineer summary from forums)

Conspiracy theories question the physics, but official analyses align on impact-plus-fire as cause, with no evidence of explosives.

In 2026, memorials honor victims, while structural codes worldwide now prioritize fire resistance post-9/11.

TL;DR: Planes hit the towers on 9/11/2001, causing fires that weakened steel and led to total collapse, killing thousands.

Information gathered from public forums or data available on the internet and portrayed here.