What caused Twin Towers to fall?

The collapse of the World Trade Center occurred during the terrorist attacks of September 11, 2001, after the Twin Towers were struck by two hijacked commercial airliners.
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What caused the steel to fail in the Twin Towers?

Thus, the failure of the steel was due to two factors: loss of strength due to the temperature of the fire, and loss of structural integrity due to distortion of the steel from the non-uniform temperatures in the fire.
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How long did it take for the Twin Towers to collapse?

10:28:22: The North Tower of the World Trade Center collapses, 1 hour and 42 minutes after the impact of Flight 11. The Marriott Hotel, located at the base of the two towers, is also destroyed. 10:50:19: Five stories of part of the Pentagon collapse due to the fire.
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Why did the South Tower fall first?

Engineers suggested that the south tower of the World Trade Center collapsed first, even though it was hit by the second plane, because the fireball caused by the crash was larger and because the plane hit the corner of the building, rather than the center, where there is more structural support.
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What caused building collapse?

Excessive weight placed on a faulty structure will cause a building collapse. Heavy machinery – during construction or demolition the weight of heavy machinery can cause the building to collapse. A mistake by a worker operating heavy machinery can cause structural damage that contributes to the building collapse.
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Flight Attendant Rant on Crashing, 9/11



Why did building in Florida collapse?

The 18-story building is located in Miami Beach, immediately south of the Champlain Towers site in Surfside. "As numerous media reports have documented, Champlain Towers South was improperly designed, poorly constructed, significantly underfunded and inadequately maintained and repaired," said attorney David B.
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What is the weakest part of a building?

The foundation is the weak point in the building's structure because it does not carry any weight. It spreads out the load from the building above it so that it does not have to bear the whole weight of the house. The door frame is the weakest part of the building because it is made up of thin wood beams.
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Did the Twin Towers sway?

Each of the Twin Towers had 110 floors. Each tower's footprint and floors were approximately an acre in size. On windy days, each tower could sway up to almost 12 inches side to side. There were 43,600 windows in the Twin Towers, equating to more than 600,000 square feet of glass.
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How many survived the collapse of the Twin Towers?

After collapses

After the towers collapsed, only 23 individuals in or below the towers escaped from the debris, including 15 rescue workers.
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Why is ground zero called Ground Zero?

Ground Zero originated as a term to describe the site of a nuclear explosion and later was used to refer to the point of any dramatic or violent event. New Yorkers started calling the World Trade Center site Ground Zero shortly after suicide hijackers destroyed the twin towers and killed nearly 3,000 people.
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What temperature do steel beams melt at?

Steel often melts at around 1370 degrees C (2500°F).
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Were the Twin Towers rebuilt?

The World Trade Center is a mostly completed complex of buildings in the Lower Manhattan neighborhood of New York City, U.S., replacing the original seven buildings on the same site that were destroyed in the September 11 attacks.
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How long after the first tower fell did the second fall?

The first fragments of the outer walls of the collapsed North Tower struck the ground 11 seconds after the collapse started, and parts of the South Tower after 9 seconds.
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Why didnt the sprinkler system work in the Twin Towers?

Unfortunately, the impacts dislodged fireproofing insulation that coated steel in the floors and columns, leaving the metal vulnerable to weakening under fire. The ceiling sprinklers also did not work, because the water supplying them was cut off by the collisions.
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How many floors did the Twin Towers have?

The Twin Towers were the centerpieces of the World Trade Center complex. At 110 stories each, 1 WTC (North Tower) and 2 WTC (South Tower) provided nearly 10 million square feet of office space for about 35,000 people and 430 companies.
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Who was the last person alive on 9 11?

The final survivor, Port Authority secretary Genelle Guzman-McMillan, was rescued 27 hours after the collapse of the North Tower. Some firefighters and civilians who survived made cell phone calls from voids beneath the rubble, though the amount of debris made it difficult for rescue workers to get to them.
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How much money did 9/11 families get?

At the end of the process $7 billion was awarded to 97% of the families. A non-negotiable clause in the acceptance papers for the settlements was that the families were to never file suit against the airlines for any lack of security or otherwise unsafe procedures.
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How hot was it inside the Twin Towers?

NIST reported maximum upper layer air temperatures of about 1,000 degrees Celsius (1,800 degrees Fahrenheit) in the WTC towers (for example, see NCSTAR 1, Figure 6-36).
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How many workers died building the Twin Towers?

In all, 60 workers were killed in construction accidents while the World Trade Center was being built. The topping out ceremony of the North Tower (1 World Trade Center) took place on December 23, 1970, while the South Tower (2 World Trade Center)'s ceremony occurred on July 19, 1971.
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How fast were the elevators in the Twin Towers?

Twin Towers' elevator speed: 1,600 feet per minute

The Twin Towers had 198 elevators operating inside 15 miles of elevator shafts, and when they were installed, their motors were the largest in the world.
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Is it better to be upstairs or downstairs in an earthquake?

In major earthquakes, it is usually safer upstairs than being on ground level. It can be dangerous trying to run hastily downstairs.
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How do you know if a building is going to collapse?

Sometimes areas of the floor will be sunken, heaved or sloped. Look for bowing floors or areas where floors are separating from walls. Cracks that start at the top corners of doors or windows and extend toward the ceiling can be a sign of a shifting foundation. Hairline cracks might not be anything to worry about.
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What is the weakest point in a door?

What are the 3 weakest points of a door? A door is usually most vulnerable at its strike plate, its hinges, and its existing lock hardware. Burglars and criminals are prone to attacking these points because that's where it's easiest to get in.
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Who owns the condo that collapsed in Miami?

Champlain condo owner Deborah Soriano, who escaped from her 11th-floor unit the night of the collapse, said she was served with a notice about the state law at her office. “Yes, I felt like a real criminal. When did [we], the victims, turn into criminals?” she said in court. “What have we really done wrong?
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