Did anyone survive the 911 incident from those two buildings?

The New York Times interviewed more than 140 people who had contact with the people trapped in the World Trade Center building at the time of the incident, as well as 17 survivors who were trapped in the attack area and above in the South Tower of the World Trade Center and finally managed to escape, and 8 survivors who were trapped on the lower floors of the North Tower attack area. Coupled with the 20 tapes taken by people in the immediate area during the incident, 15 hours of tapes recorded by New York** and the fire department, and a summary of the 911 emergency**, it was put together.

Of the 2,823 911 New York victims, 1,946 were at the top of the sister buildings of the World Trade Center at the time: 1,344 on the 91,110th floor of the North Tower and 602 on the 78,110th floor of the South Tower. According to the video tapes collected, more than 37 people jumped from a height of 1 4 miles in the North Block.

Of these, 26 Chinese were killed).

Evidence suggests that at least 1,100 people were still alive on top of both towers between the time the two planes crashed into the World Trade Center and the building collapsed. At least 353 of them were in contact with the outside world when they were trapped, leaving affectionate and permanent messages to their relatives and friends in the last moments of their lives.

Of the dead and missing, 2,940 died or were missing in the attack on the World Trade Center, 189 were killed when the **** plane crashed into the Pentagon, and 44 were killed when the **** hijacked plane crashed in Pennsylvania. So far, rescuers have recovered the bodies of 573 victims from the rubble of the World Trade Center. In addition, the rest of the tens of thousands of people in the World Trade Center at that time had escaped immediately.

At 8:40 a.m. EST on September 11, 2001, four U.S. domestic civil aviation flights were hijacked almost simultaneously, two of which hit the world** center in Manhattan, New York, and one hit the Pentagon, the seat of the U.S. Department of Defense in Washington, D.C.

As the United States, the world's largest country, two such important buildings, of course, there will be 24-hour internal and external surveillance, so it is normal to take pictures.

Among the various arguments in the American intellectual circles, the theory of "clash of civilizations" has become one of the main arguments for interpreting the root cause of the "11 September" incident. Many of the world's leading countries point to the fact that the important source of terrorism is the United States' Middle East policy. The protracted Israeli and Palestinian military conflicts, the killing of Palestinians by Israelis, and the partiality of the United States towards Israel have "created" fanatical radicals with a determination to die.

The BBC and Le Monde have both pointed out that "the crux of the problem lies in the US Middle East policy." The British newspaper The Guardian, headlined "The Best Defense Is Justice," pointed out that Americans must be "fair" "in order to really stop the widespread support that Osama enjoys in Arab and Muslim societies." ”

There is an opinion that the attack was a political conspiracy. Among the main doubts were the possibility that the plane would crash into a skyscraper, the Pentagon's notch diameter did not match the diameter of the plane, the debris of United Airlines Flight 93 and the life and death of the hijackers. Conspiracy theorists believe that the purpose of the attack was to maintain the international status of the United States and achieve the goal of hegemony and peace in order to control the world.

From the perspective of engineering mechanics, the analysis is as follows: the main structure of the World Trade Center in 911 is a cylinder structure, that is, the inside is a steel skeleton (a large steel skeleton is covered by a concrete protective layer), and the outside is an enclosure structure (glass curtain wall, concrete frame, and infill wall). Then the process of collapse should be as follows:

1. The plane crashed into the middle of the building, destroying the outer protective layer of the main structure;

2. The fuel on the plane poured into the middle floor and ignited a raging fire;

3. The high temperature generated by combustion causes the main steel skeleton to soften after a period of time, and the strength is obviously closed;

4. The steel supporting the upper floor reaches the critical point of strength, and the collapse occurs before the occurrence.

5. The impact of the collapse of the superstructure crushes the structure below, resulting in a chain reaction.

That's pretty much it. The Achilles' heel of the steel structure is that it is fireproof and not resistant to high temperatures.