The twins towers-Petronas Towers - Wikipedia

This article is part of our series of explainers on key moments in the past years of world political history. In it, our authors examine how and why an event unfolded, its impact at the time, and its relevance to politics today. As the news was beamed around the world, shaken reporters wondered whether the crash had been an accident or an act of terrorism. At am, viewers watching the smoke billowing from the gash in the building were stunned to see a second jet plane dart into view and fly directly into the South Tower. Suddenly, it was clear that the United States was under attack.

The twins towers

World Trade Center — World's tallest building architectural element New York: Fordham University Press. Archived from the original on January 5, Tallest in the world from to [I]. Archived from the original on February 4, Retrieved December 1

Teens post pic. A history of the Manhattan landmark destroyed on September 11, 2001

Watch now. New York Post. Another 2 wins. Thus, it was nicknamed Trump Twin Towers by media. Star: Tommy Buda. On September 11,the World Trade Center became the target The twins towers a massive terrorist attack that took the lives of nearly gowers, people. Inpublicity Loving tenderness the The twins towers increased, with businessman Donald Trump officially supporting and sponsoring the project. Windows towdrs the World was closed following the World Trade Center bombing. Archived from the original on November 9, Archived from the original on February 22, The project involved combining the twelve-block area bounded by Vesey, Church, Liberty, and West Streets on the north, east, south, and west, respectively. World Trade Center —

In the years since the terrorist attacks in New York City, individual engineers and committees of experts have studied the crumpling of the World Trade Center twin towers.

  • Sign in.
  • After the September 11 attacks in , several ideas about building new twin towers were discussed online and in the media.
  • In the years since the terrorist attacks in New York City, individual engineers and committees of experts have studied the crumpling of the World Trade Center twin towers.
  • It opened on April 4, , and was destroyed in during the September 11 attacks.
  • Completed in , the towers stood at stories each, accommodating 50, workers and , daily visitors in 10 million square feet of space.
  • .

Completed in , the towers stood at stories each, accommodating 50, workers and , daily visitors in 10 million square feet of space. On September 11, , the World Trade Center became the target of a massive terrorist attack that took the lives of nearly 3, people.

The disaster also radically altered the skyline of New York City, destroying the twin columns of glass and steel that over the years had come to embody the city itself. Aldrich, headed a new state agency with the proposed goal of creating a permanent trade exposition based in New York. Market research indicated that the city would benefit more by modernizing its ports, however, and the plan was soon scrapped.

The grandson of Standard Oil founder John D. Rockefeller , David decided to revive the World Trade Center concept as the core of a revitalized lower Manhattan. For the resources and power to make the project work, Rockefeller turned to the Port of New York Authority. The Port Authority had been chartered in by New York and New Jersey to build and operate all transportation terminals and facilities within a mile radius of the Statue of Liberty.

After a bitter legal battle with representatives of the Radio Row merchants, the Port Authority won the right to continue its plan. Instead of the traditional stacked glass-and-steel box construction of many New York skyscrapers, Yamasaki worked with structural engineers to come up with a revolutionary design: two hollow tubes, supported by closely spaced steel columns encased in aluminum.

Floor trusses connected this exterior steel lattice to the central steel core of the building. Wien even ran an ad in the New York Times in May predicting that a commercial airliner was likely to fly into the towers.

Plans had already been made to guard against such an accident—which had happened in July with a smaller plane at the Empire State—and the towers were designed to be safe in a collision with a fully loaded plane the largest existing plane at the time.

It was assumed such a plane would have to be lost in fog for such an event to occur; a terrorist attack was never envisioned. View of the World Trade Center under construction, with a sign announcing the completion schedule, circa Because the ground in lower Manhattan was largely landfill, engineers would have to dig down 70 feet to reach bedrock. Excavating machines dug a three-foot-wide trench down to the bedrock, and as dirt and rock were removed, they were replaced by slurry: a mixture of water and bentonite, a type of clay that expands when wet to plug any hole along the side of the trench.

Workers then lowered a ton, seven-story-high steel cage into the trench and filled it with concrete by using a long pipe. As the concrete flowed in, it displaced the bentonite slurry. By making more than of these slurry trench segments, workers enclosed an area two blocks wide and four blocks long. All in all, one million cubic yards of landfill had to be removed. At the end of construction, these cranes had to be disassembled and brought down by elevator.

When the towers were finished, each one would have 97 passenger elevators, capable of carrying loads of up to 10, pounds at speeds of up to 1, feet per minute. In all, the towers were assembled from more than , pieces of steel manufactured around the country, 3, miles of electrical wiring, , cubic yards of concrete, 40, doors, 43, windows and six acres of marble.

Construction went on until April , when the five-acre outdoor plaza, dominated by a foot-tall bronze sculpture by Fritz Koenig, was completed. Today, we have. Still, the towers held an incomparable mystique. They inspired incredible stunts, beginning in August , when Philippe Petit walked a high wire between the two towers. The Port Authority loved these stunts because they endeared the towers to the public and made them seem like giant toys.

They worked at turning the towers into an attraction, adding the Windows on the World restaurant, which opened on the th floor of the north tower in April and was an immediate hit.

Smaller importers-exporters were now being pushed out by rising rents, making way for major businesses. Six Islamic extremists were tried and convicted in connection with the plot.

The towers reopened 20 days after the bombing with new security measures in place, including restrictions to parking lot access and electronic identification badges for building tenants. In July , just two months before the terrorist attacks of September 11, the Port Authority agreed to lease the twin towers to Larry Silverstein, a New York City developer. At the time, over 99 percent of the The first plane ripped a hole in the north tower from the 94th to the 98th floors, causing massive structural damage and igniting some 3, of the 10, gallons of jet fuel the plane was carrying.

The second plane hit the south tower at an even faster speed, striking the corner and gashing the building from the 84th to the 78th floors.

The damage done at each point of impact forced the physical weight of the towers to be redistributed, and the undamaged part below the hole had to support the floors above.

At the same time, the fires raging in both buildings weakened the steel trusses holding up each floor. With damage to a greater number of floors lower down on the building, the south tower gave way first, crumbling to the ground at a.

The north tower collapsed less than a half hour later, at a. Debris from the falling towers ignited fires in the remaining buildings of the trade center complex, including 7 World Trade, which burned for most of the day before collapsing at p. Built on the original 6 World Trade Center, it was originally designed by architect Daniel Libeskind to be an asymmetrical tower inspired by the Statue of Liberty.

The cornerstone was laid on July 4, , but the building did not open until November 3, One World Trade is stories tall and has three million square feet of office space topped off by One World Observatory, an observation deck, bar, and restaurant open to the pubic. It spans from floors and offers visitors panoramic views of New York City. A new tower at 7 World Trade Center opened in The World Trade Center Oculus, a glass and steel transit concourse and shopping center designed by the Spanish architect Santiago Calatrava, opened to the public in , while the 1, foot tall 3 World Trade Center opened in But if you see something that doesn't look right, click here to contact us!

Subscribe for fascinating stories connecting the past to the present. I heard whooshing sounds… One of the most vivid pictures I have of the day is this waterfall of fire falling down. Follow me! On September 11, , 19 militants associated with the Islamic extremist group al Qaeda hijacked four airplanes and carried out suicide attacks against targets in the United States. On the morning of July 13, , the roar of backhoes and bulldozers echoed through lower Manhattan as construction continued on the rebirth of the World Trade Center site, which had been destroyed nearly nine years earlier in the worst terrorist attack in American history.

On September 11, —a clear, sunny, late summer day—al Qaeda terrorists aboard three hijacked passenger planes carried out coordinated suicide attacks against the World Trade Center in New York City and the Pentagon in Washington, D. The September 11 attacks struck the nation on a clear, late summer morning on the East Coast. One hijacked plane crashed in a field outside Shanksville, Pennsylvania. Shortly after the Twin Towers fell on September 11, , the nation began to mourn, and around the country Americans began to commemorate the victims and demonstrate their patriotism.

Some flew the American flag from their front porches and car antennas. Others pinned it to On the morning of September 11, , the deadliest terrorist attack in U. This Day In History. The Port Authority Signs On. World Trade Center. Clinton on the World Trade Center Bombing. Tree Rings Solve World Trade Center Ship Mystery On the morning of July 13, , the roar of backhoes and bulldozers echoed through lower Manhattan as construction continued on the rebirth of the World Trade Center site, which had been destroyed nearly nine years earlier in the worst terrorist attack in American history.

Soil The September 11 attacks struck the nation on a clear, late summer morning on the East Coast. Flight 93 On the morning of September 11, , the deadliest terrorist attack in U.

Archived from the original on October 30, June 12, McAllister September The second plane hit the south tower at an even faster speed, striking the corner and gashing the building from the 84th to the 78th floors. After the September 11 attacks in , several ideas about building new twin towers were discussed online and in the media. David Ray. Plot Summary.

The twins towers

The twins towers

The twins towers

The twins towers

The twins towers. Secondary menu

After they collapsed, the hollow core was gone. The remaining rubble was only a few stories high. The twin towers were built between and No building constructed at that time would have been able to withstand the impact of the terrorist attacks in We can, however, learn from the collapse of the skyscrapers and take steps to construct safer buildings and minimize the number of casualties in future disasters. When the twin towers were constructed, the builders were granted some exemptions from New York's building codes.

The exemptions allowed the builders to use lightweight materials so the skyscrapers could achieve great heights. Others say the architectural design actually saved lives. These skyscrapers were designed with redundancies—anticipating that a small plane could accidentally penetrate the skyscraper skin and the building would not fall from that type of accident.

The north tower was hit at a. ET, between floors 94 and 98—it did not collapse until a. Even the south tower was able to stand for a remarkable 56 minutes after being hit at a.

The second jet hit the south tower on lower floors, between floors 78 and 84, which structurally compromised the skyscraper earlier than the north tower. Most of the south tower occupants, however, began evacuating when the north tower was hit. The towers could not have been designed any better or stronger.

Nobody anticipated the deliberate actions of an aircraft filled with thousands of gallons of jet fuel. Conspiracy theories often accompany horrific and tragic events. Some occurrences in life are so shockingly incomprehensible that some people begin to doubt theories. They might reinterpret evidence and offer explanations based on their prior knowledge. Passionate people fabricate what becomes alternative logical reasoning. When the buildings collapsed, some thought it had all of the characteristics of a "controlled demolition.

Some people believe that the twin towers were brought down by explosives, although others find no evidence for this belief. Writing in the Journal of Engineering Mechanics ASCE, researchers have shown "the allegations of controlled demolition to be absurd" and that the towers "failed due to gravity-driven progressive collapse triggered by the effects of fire.

Engineers examine evidence and create conclusions based on observations. On the other hand, the Movement seeks the "suppressed realities of September 11th" that will support their mission.

Conspiracy theories tend to continue in spite of the evidence. While architects strive to design safe buildings, developers don't always want to pay for over-redundancies to mitigate outcomes of events that are unlikely to happen.

Tall office buildings are required to have more durable fireproofing, extra emergency exits, and many other fire safety features. Share Flipboard Email. Table of Contents Expand. Aircraft Impact. Heat From Fires. Collapsing Floors. Why They Flattened. Strong Enough? Legacy on Building. Completed in , the towers stood at stories each, accommodating 50, workers and , daily visitors in 10 million square feet of space.

On September 11, , the World Trade Center became the target of a massive terrorist attack that took the lives of nearly 3, people. The disaster also radically altered the skyline of New York City, destroying the twin columns of glass and steel that over the years had come to embody the city itself. Aldrich, headed a new state agency with the proposed goal of creating a permanent trade exposition based in New York. Market research indicated that the city would benefit more by modernizing its ports, however, and the plan was soon scrapped.

The grandson of Standard Oil founder John D. Rockefeller , David decided to revive the World Trade Center concept as the core of a revitalized lower Manhattan. For the resources and power to make the project work, Rockefeller turned to the Port of New York Authority.

The Port Authority had been chartered in by New York and New Jersey to build and operate all transportation terminals and facilities within a mile radius of the Statue of Liberty. After a bitter legal battle with representatives of the Radio Row merchants, the Port Authority won the right to continue its plan.

Instead of the traditional stacked glass-and-steel box construction of many New York skyscrapers, Yamasaki worked with structural engineers to come up with a revolutionary design: two hollow tubes, supported by closely spaced steel columns encased in aluminum.

Floor trusses connected this exterior steel lattice to the central steel core of the building. Wien even ran an ad in the New York Times in May predicting that a commercial airliner was likely to fly into the towers.

Plans had already been made to guard against such an accident—which had happened in July with a smaller plane at the Empire State—and the towers were designed to be safe in a collision with a fully loaded plane the largest existing plane at the time. It was assumed such a plane would have to be lost in fog for such an event to occur; a terrorist attack was never envisioned.

View of the World Trade Center under construction, with a sign announcing the completion schedule, circa Because the ground in lower Manhattan was largely landfill, engineers would have to dig down 70 feet to reach bedrock.

Excavating machines dug a three-foot-wide trench down to the bedrock, and as dirt and rock were removed, they were replaced by slurry: a mixture of water and bentonite, a type of clay that expands when wet to plug any hole along the side of the trench.

Workers then lowered a ton, seven-story-high steel cage into the trench and filled it with concrete by using a long pipe. As the concrete flowed in, it displaced the bentonite slurry. By making more than of these slurry trench segments, workers enclosed an area two blocks wide and four blocks long. All in all, one million cubic yards of landfill had to be removed. At the end of construction, these cranes had to be disassembled and brought down by elevator.

When the towers were finished, each one would have 97 passenger elevators, capable of carrying loads of up to 10, pounds at speeds of up to 1, feet per minute.

In all, the towers were assembled from more than , pieces of steel manufactured around the country, 3, miles of electrical wiring, , cubic yards of concrete, 40, doors, 43, windows and six acres of marble. Construction went on until April , when the five-acre outdoor plaza, dominated by a foot-tall bronze sculpture by Fritz Koenig, was completed. Today, we have. Still, the towers held an incomparable mystique. They inspired incredible stunts, beginning in August , when Philippe Petit walked a high wire between the two towers.

The Port Authority loved these stunts because they endeared the towers to the public and made them seem like giant toys. They worked at turning the towers into an attraction, adding the Windows on the World restaurant, which opened on the th floor of the north tower in April and was an immediate hit. Smaller importers-exporters were now being pushed out by rising rents, making way for major businesses.

Six Islamic extremists were tried and convicted in connection with the plot. The towers reopened 20 days after the bombing with new security measures in place, including restrictions to parking lot access and electronic identification badges for building tenants.

The Twin Towers Collapse Explained

It opened on April 4, , and was destroyed in during the September 11 attacks. It awarded the lease to Silverstein Properties in July On the morning of September 11, , Al-Qaeda -affiliated hijackers flew two Boeing jets into the North and South Towers within minutes of each other; two hours later, both towers collapsed. The attacks killed 2, people in and within the vicinity of the towers, as well as all on board the two aircraft. The cleanup and recovery process at the World Trade Center site took eight months, during which the remains of the other buildings were demolished.

A new World Trade Center complex is being built with six new skyscrapers and several other buildings, many of which have already been completed. A memorial and museum to those killed in the attacks, a new rapid transit hub , and an elevated park have been opened. Following the World Trade Center's destruction, mentions of the complex were altered or deleted, and several dozen "memorial films" were created.

The shoreline was in the vicinity of Greenwich Street, which is closer to the site's eastern border. It was on this shoreline, close to the intersection of Greenwich and the former Dey Street, that Dutch explorer Adriaen Block 's ship, Tyger , burned to the waterline in November , stranding him and his crew and forcing them to overwinter on the island. They built the first European settlement in Manhattan. The remains of the ship were buried under landfill when the shoreline was extended beginning in and were discovered during excavation work in The remains of a second eighteenth century ship were discovered in during excavation work at the site.

The ship, believed to be a Hudson River sloop , was found just south of where the Twin Towers stood, about 20 feet 6. The neighborhood was a warehouse district in what is now Tribeca and the Financial District. Harry Schneck opened City Radio on Cortlandt Street in , and eventually the area held several blocks of electronics stores, with Cortlandt Street as its central axis.

The used radios, war surplus electronics e. According to a business writer, it also was the origin of the electronic component distribution business. Dewey to begin developing plans for the project, [15] but the plans were put on hold in Plans for the use of eminent domain to remove the shops in Radio Row bounded by Vesey , Church , Liberty , and West Streets began in when the Port Authority of New York and New Jersey was deciding to build the world's first world trade center.

New Jersey Governor Robert B. Disagreements with the city centered on tax issues. On August 3 , , an agreement was reached whereby the Port Authority would make annual payments to the City in lieu of taxes for the portion of the World Trade Center leased to private tenants.

A major limiting factor in building height is the issue of elevators; the taller the building, the more elevators are needed to service it, requiring more space-consuming elevator banks. This system, inspired by the local-express train operation used in New York City's subway system, [41] allowed the design to stack local elevators within the same elevator shaft. Located on the 44th and 78th floors of each tower, the sky lobbies enabled the elevators to be used efficiently.

This increased the amount of usable space on each floor from 62 to 75 percent by reducing the number of elevator shafts. Guy F. Monti, the Port Authority's Chief Engineer, oversaw the project.

Nonetheless, the World Trade Center's structural engineers ended up following draft versions of New York City's new building codes. The framed-tube design, introduced in the s by Bangladeshi-American structural engineer Fazlur Rahman Khan , [47] was a new approach that allowed more open floor plans than the traditional design that distributed columns throughout the interior to support building loads.

Each of the World Trade Center towers had high-strength, load-bearing perimeter steel columns which acted as Vierendeel trusses. The spandrel plates were located at each floor, transmitting shear stress between columns, allowing them to work together in resisting lateral loads.

The joints between modules were staggered vertically, so that the column splices between adjacent modules were not at the same floor. The core of the towers housed the elevator and utility shafts, restrooms, three stairwells, and other support spaces. The large, column-free space between the perimeter and core was bridged by prefabricated floor trusses.

The floors supported their own weight as well as live loads , providing lateral stability to the exterior walls and distributing wind loads among the exterior walls. A grid of lightweight bridging trusses and main trusses supported the floors. The top chords of the trusses were bolted to seats welded to the spandrels on the exterior side and a channel welded to the core columns on the interior side.

The floors were connected to the perimeter spandrel plates with viscoelastic dampers that helped reduce the amount of sway felt by building occupants. Hat trusses or "outrigger trusses" located from the th floor to the top of the buildings were designed to support a tall communication antenna on top of each building. This truss system allowed some load redistribution between the perimeter and core columns and supported the transmission tower.

The framed-tube design, using steel core and perimeter columns protected with sprayed-on fire resistant material, created a relatively lightweight structure that would sway more in response to the wind compared to traditional structures, such as the Empire State Building that have thick, heavy masonry for fireproofing of steel structural elements.

Davenport to develop viscoelastic dampers to absorb some of the sway. These viscoelastic dampers, used throughout the structures at the joints between floor trusses and perimeter columns along with some other structural modifications, reduced the building sway to an acceptable level.

Kyle, Jr. When the trench was dug out, a steel cage was inserted and concrete was poured in, forcing the "slurry" out. It took fourteen months for the slurry wall to be completed. It was necessary before excavation of material from the interior of the site could begin. In addition to the twin towers, the plan for the World Trade Center complex included four other low-rise buildings, which were built in the early s.

Plans to build the World Trade Center were controversial. Its site was the location of Radio Row, home to hundreds of commercial and industrial tenants, property owners, small businesses, and approximately residents, many of whom fiercely resisted forced relocation.

Wien , expressed concerns about this much "subsidized" office space going on the open market, competing with the private sector, when there was already a glut of vacancies. The World Trade Center's design aesthetics attracted criticism from the American Institute of Architects and other groups.

Some critics regarded the trade center's "superblock", replacing a more traditional, dense neighborhood , as an inhospitable environment that disrupted the complicated traffic network typical of Manhattan. For example, in his book The Pentagon of Power , Lewis Mumford denounced the center as an "example of the purposeless giantism and technological exhibitionism that are now eviscerating the living tissue of every great city".

In , the immense plaza between the twin towers was renamed after the Port Authority's late chairman, Austin J. This involved replacing marble pavers with gray and pink granite stones, adding new benches, planters, new restaurants, food kiosks and outdoor dining areas.

The World Trade Center complex housed more than companies that were engaged in various commercial activities. The Twin Towers became known worldwide, appearing in numerous movies and television shows as well as on postcards and other merchandise.

One World Trade Center and Two World Trade Center, commonly referred to as the Twin Towers, were designed by architect Minoru Yamasaki as framed tube structures, which provided tenants with open floor plans, uninterrupted by columns or walls.

During a press conference in , Yamasaki was asked, "Why two story buildings? Why not one story building? Throughout their existence, the twin towers had more floors at than any other building. Although most of the space in the World Trade Center complex was off-limits to the public, the South Tower featured a public observation deck on the th floor called Top of the World. The Port Authority renovated the observatory in , then leased it to Ogden Entertainment to operate.

Attractions added to the observation deck included a theater showing a film of a helicopter tour around the city. This left the view unobstructed, unlike the observation deck of the Empire State Building. Windows on the World, the restaurant on the North Tower's th and th floors, opened in April Windows on the World was closed following the World Trade Center bombing.

In its last iteration, Windows on the World received mixed reviews. Ruth Reichl , a New York Times food critic, said in December that "nobody will ever go to Windows on the World just to eat, but even the fussiest food person can now be content dining at one of New York's favorite tourist destinations". She gave the restaurant two out of four stars, signifying a "very good" quality. He said, "Windows helped usher in a new era of captive audience dining in that the restaurant was a destination in itself, rather than a lazy by-product of the vital institution it resided in.

Commodities Exchange. One of the world's largest gold depositories was located underneath the World Trade Center, owned by a group of commercial banks. The bombing detonated close to the vault. This included 3, Troy-ounce 24 carat gold bars and 30, 1,ounce silver bars. On February 13, , a three-alarm fire broke out on the 11th floor of the North Tower. It spread to the 9th and 14th floors after igniting telephone cable insulation in a utility shaft that ran vertically between floors.

Areas at the furthest extent of the fire were extinguished almost immediately; the original fire was put out in a few hours. Most of the damage was concentrated on the 11th floor, fueled by cabinets filled with paper, alcohol-based fluid for office machines, and other office equipment. Fireproofing protected the steel and there was no structural damage to the tower.

In addition to fire damage on the 9th through the 14th floors, the water used to extinguish the fire damaged a few of the floors below. At that time, the World Trade Center had no fire sprinkler systems. Following the bombing, floors that were blown out needed to be repaired to restore the structural support they provided to columns.

The refrigeration plant on sublevel B5, which provided air conditioning to the entire World Trade Center complex, was heavily damaged. The aircraft, which was scheduled to land at nearby JFK Airport , was flying at a much lower altitude than regulations recommended. In , the Port Authority approved plans to privatize the World Trade Center, [] and in sought to lease it to a private entity.

However, Vornado insisted on last minute changes to the deal, including a shorter year lease, which the Port Authority considered nonnegotiable. Although the South Tower was struck lower than the North Tower, thus affecting more floors, a smaller number, fewer than , were killed instantly or trapped. The fire caused steel structural elements, already weakened from the plane's impact, to fail. The Marriott World Trade Center hotel was destroyed during the collapse of the two towers.

The three remaining buildings in the WTC plaza were extensively damaged by debris and were later demolished. In the immediate aftermath of the attacks, media reports suggested that tens of thousands might have been killed in the attacks, as over 50, people could have been inside the World Trade Center. Over the following years, plans were created for the reconstruction of the World Trade Center.

The Lower Manhattan Development Corporation LMDC , established in November to oversee the rebuilding process, [] organized competitions to select a site plan and memorial design. In November , according to an agreement made with Silverstein Properties Inc. The original World Trade Center created a superblock that cut through the area's street grid, isolating the complex from the rest of the community.

The twins towers