It was a Tuesday. People usually remember the weather first—that specific, piercingly clear blue sky that you only get in New York during early September. Then the first plane hit the North Tower.
Most of us who watched it live, or saw the smoke pouring out of the 110-story monolith on the news, initially thought it was a tragic accident. A small Cessna, maybe? A pilot having a heart attack? Then the second plane, United Airlines Flight 175, banked hard over the harbor and sliced into the South Tower. That was the moment the collective "we" realized this wasn't an accident. It was an attack.
The plane hitting the twin towers remains the most documented, analyzed, and culturally significant event of the 21st century. Even now, decades later, there are details about the physics, the communication breakdowns, and the sheer scale of the day that many people still get wrong.
The Physics of the Impact: Why the Towers Fell
There’s a persistent myth that the buildings should have stood because they were "designed to withstand a Boeing 707." Technically, that’s true. The lead structural engineer, John Skilling, noted in the 60s that the towers could take the hit of a jet. But here is the thing: a Boeing 707 is significantly smaller and slower than the Boeing 767s used on 9/11.
American Airlines Flight 11 hit the North Tower at roughly 440 mph. United 175 hit the South Tower at a staggering 540 mph.
The buildings didn't fall because of the initial impact force. They fell because the "tube-frame" design, while revolutionary, relied on a series of perimeter columns to carry the load. When the planes sliced through those steel columns, the weight of the building was redistributed to the remaining structure. Then the fire started.
It wasn’t just the jet fuel. Jet fuel burns at about 800°F to 1500°F. Steel doesn't melt until 2750°F. You’ve probably heard the "jet fuel can't melt steel beams" trope online, but it misses the fundamental engineering reality. Steel begins to lose about 50% of its structural strength at 1100°F. When you combine that weakened steel with the weight of thirty floors of office furniture, paper, and equipment—all of which were also on fire—the floor trusses began to sag.
✨ Don't miss: Ohio Polls Explained: What Most People Get Wrong About Voting Times
The South Tower actually collapsed first, even though it was hit second. Why? Because the plane hit it lower down, between floors 77 and 85, putting much more weight on the damaged area. The North Tower was hit higher up, between floors 93 and 99, allowing it to hold on for almost two hours before the structural failure became inevitable.
The Misunderstood Communication Breakdown
If you look back at the 9/11 Commission Report, one of the most heartbreaking sections involves the communication failure within the buildings.
Inside the South Tower, many people actually started to evacuate after the first plane hit the North Tower. However, an announcement was made over the PA system telling people the building was secure and they could return to their offices. This wasn't a conspiracy or a mistake born of malice. The Port Authority was following standard high-rise fire protocols of the era: stay put unless your floor is specifically in danger to avoid clogging the stairwells for emergency responders.
That "stay put" advice likely cost hundreds of lives.
When the second plane hitting the twin towers occurred just 17 minutes later, those who had stayed or returned were trapped above the impact zone. In the North Tower, not a single person above the 91st floor survived. The impact had severed every single stairwell. In the South Tower, one stairwell (Stairwell A) remained miraculously passable, but because of the smoke and lack of information, only 18 people managed to use it to escape from above the impact zone before the collapse.
The Environmental Aftermath No One Talked About
We often focus on the fire and the collapse, but the air was the silent killer. When those buildings came down, they pulverized everything inside. Computers, lead-based paint, asbestos, mercury, and 200,000 gallons of heating oil were turned into a microscopic toxic dust.
🔗 Read more: Obituaries Binghamton New York: Why Finding Local History is Getting Harder
The EPA, under Christie Todd Whitman, famously declared the air "safe to breathe" just days later. That was a catastrophic error.
We now know that more people have died from 9/11-related illnesses—including rare cancers and respiratory diseases—than the 2,977 people who died on the day of the attacks. The World Trade Center Health Program currently monitors over 120,000 responders and survivors. It’s a lingering health crisis that proves the event didn't end when the towers fell. It just changed shape.
Why Technical Accuracy Matters for History
People often ask why we still dissect the footage. Why do we need to know the exact floor numbers or the flight speeds?
Because history gets blurry when we rely on emotion alone.
When you understand that the North Tower's antenna was the first thing to drop during the collapse, it tells you that the core columns failed first. When you realize the planes were specifically chosen for long-haul transcontinental flights to ensure they had maximum fuel loads, you realize the tactical precision of the attackers.
There are also the stories of "The Red Bandanna," Welles Crowther, who used his training as a volunteer firefighter to lead groups to safety in the South Tower, or the blind man, Michael Hingson, whose guide dog Roselle led him down 78 flights of stairs through the chaos. These aren't just feel-good anecdotes. They are documented evidence of human resiliency in the face of a structural and psychological catastrophe.
💡 You might also like: NYC Subway 6 Train Delay: What Actually Happens Under Lexington Avenue
Navigating the Legacy Today
If you visit the 9/11 Memorial & Museum today, you'll see the "slurry wall." It was the underground retaining wall designed to keep the Hudson River from flooding the site. Engineers were terrified that the collapse of the towers would cause the wall to fail, which would have flooded the NYC subway system and potentially killed thousands more. It held. Barely.
Today, the site is a place of reflection, but it is also a reminder of architectural evolution. The new One World Trade Center isn't a tube-frame design. It features a massive, reinforced concrete core and a "life safety" staircase specifically designed for first responders to go up while civilians go down.
How to Research This Responsibly
If you are looking to dig deeper into the mechanics of that day, avoid the sensationalist YouTube "truth" documentaries. They often ignore the laws of thermodynamics and structural load. Instead, look at:
- The NIST (National Institute of Standards and Technology) Federal Building and Fire Safety Investigation: This is the definitive technical breakdown of why the buildings collapsed.
- The 9/11 Commission Report: This covers the intelligence and communication failures. It reads like a thriller, honestly, and it’s deeply revealing about the "system" failures.
- The New York State Museum’s 9/11 Collection: They have preserved physical artifacts, from fire trucks to personal items, which provide a grounding reality to the abstract numbers.
The event of a plane hitting the twin towers changed how we travel, how we design buildings, and how we view global security. But beyond the geopolitics, it was a day of physics, flawed protocols, and incredible individual bravery. Knowing the facts helps us honor the reality of what happened, rather than the myths that have cropped up in its wake.
Take a moment to look at the architectural diagrams of the original WTC. See how the "hat truss" at the top of the towers tied the core and perimeter together. When you see the complexity of that design, you realize that the fact they stood for as long as they did after the impact is actually an engineering miracle, providing enough time for thousands of people to get out alive. It was a dark day, but the data proves it could have been even darker if the buildings hadn't been as tough as they were.
To truly grasp the scale, look into the "Man in the White Shirt" or the "Last Man Out" accounts. These primary sources offer a perspective that raw data cannot—the sound of the building groaning, the smell of the jet fuel, and the strange, eerie silence that fell over Lower Manhattan right before the first collapse. Information is our best tool for keeping the memory of that day accurate and respectful.