A 20th hijacker is a hypothetical additional terrorist in the September 11, 2001 attacks who was not able to participate. A hypothesis (from ancient Greek hypotithenai meaning to put under or to suppose) offers a proposed explanation for a phenomenon. ... The term terrorism is largely synonymous with political violence or the threat of violence, and refers to a strategy of using coordinated attacks that typically fall within the time, manner of conduct, and place commonly understood as unconventional warfare. ... A huge plume of smoke and fire can be seen emerging from the North Tower. ...

The term is somewhat misleading, as there is no evidence that al-Qaeda ever planned to have exactly twenty hijackers. There were many variations of the 9/11 plot, with the number of terrorists fluctuating with available resources and changing circumstance. In the end, there were nineteen hijackers: three of the planes were taken over by five members each, and the fourth was hijacked by only four people. Because one plane, United Airlines Flight 93, had fewer hijackers than the rest, the idea of a 20th hijacker came to be widely discussed. A huge plume of smoke and fire can be seen emerging from the North Tower. ... September 11, 2001 attacks timeline Background History 1972: One World Trade Center completed. ... At the beginning of the 21st century, the United States strongest allies in west Asia are Turkey (a member of NATO), Israel and Egypt. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... The September 11, 2001 attacks are amongst the deadliest acts of non-state terrorism in modern history, and were experienced as a traumatic, epoch-making event by many millions of people, both in the United States and beyond. ... All times, except where otherwise noted, in New York Time (EDT). ... All times, except where otherwise noted, in New York Time (EDT). ... This article talks about the aftermath of the September 11, 2001 attacks. ... Any tributes to the individuals hurt or injured in this tragedy are welcome and encouraged at our memorial site // New York City According to the 9/11 Commisson, approximately 16,400 to 18,800 civilians were in the World Trade Center complex at the time of the attacks. ... Any tributes to the individuals lost in this tragedy are welcome and encouraged at our memorial site Australia: 10 Belarus: 1 [1] Belgium: 1 Bermuda: 1 Brazil: 3 Canada: 24 Chile: 2 China: 4 Côte dIvoire: 1 Colombia: 17 Democratic Republic of the Congo: 2 Dominican Republic: 1... American Airlines Flight 11 was an American Airlines flight aboard a Boeing 767-223ER, N334AA aircraft. ... United Airlines Flight 175 was a morning flight that regularly flew from Logan International Airport in Boston, Massachusetts, to LAX in Los Angeles, California (Boston-Los Angeles route). ... Security camera image of the moment of the attack on the Pentagon. ... United Airlines Flight 93, a flight aboard a Boeing 757-222, was a flight that regularly flew from Newark International Airport (now known as Newark Liberty International Airport) in Newark, New Jersey, to San Francisco International Airport continuing on to Narita International Airport in Tokyo, Japan, on a different aircraft. ... The World Trade Center in New York City (sometimes informally referred to as the WTC or the Twin Towers) was a complex of seven buildings mostly designed by Japanese-American architect Minoru Yamasaki and developed by the Port Authority of New York and New Jersey. ... A pre-9/11 view of The Pentagon, looking east with the Potomac River and Washington Monument in the distance. ... Photo of George W. Bush and Laura Bush visiting Shanksville on September 11, 2002 Shanksville is a borough located in Somerset County, Pennsylvania. ... The following worldwide effects arose from the September 11, 2001 attacks: All United Kingdom military bases increased their level of security awareness. ... It is usually claimed that the September 11, 2001 attacks had immediate and far-ranging economic effects. ... Soon after the September 11, 2001 attacks, the U.S. government began detaining people who fit the profile of the suspected hijackers: mostly male, Arabic or Muslim non-citizens. ... Box-cutter knives were apparently used in the September 11, 2001 attacks, though such knives are not usually considered weapons. ... Following the September 11, 2001 attacks, several institutions responded with closures, cancellations, and postponements. ... The terrorist attacks of September 11, 2001 had an important impact on the audiovisual entertainment business, not just in terms of television coverage. ... // Military response The United States government has announced its intentions to engage in a protracted war against terrorists and states which aid terrorists in response to the attacks. ... The area surrounding the World Trade Center became the site of the greatest number of casualties and missing, and physical destruction. ... Charities and relief agencies raised over $657 million in the three weeks following the September 11, 2001 attacks, the vast bulk going to immediate survivors and victims families. ... The first memorials to the victims of the September 11, 2001 attacks began to take shape online, as hundreds of webmasters posted their own thoughts, links to the Red Cross, and other rescue agencies, photos and eyewitness accounts. ... Responsibility for the September 11, 2001 attacks has been found to lie with Osama bin Laden and his organization al-Qaeda. ... Many individuals were directly responsible for the September 11, 2001 attacks. ... Communications problems and successes played an important role in the September 11, 2001 attacks and their aftermath. ... A New York City firefighter looks up at the remains of the World Trade Center, two days after its collapse The Collapse of the World Trade Center was caused by the September 11, 2001 attacks that sent one hijacked airliner into each of the main towers of the World Trade... Various terms and catchphrases Nine-eleven (or 9/11 in the US date notation for September 11th) Lets roll—the last known words of Todd Beamer. ... A number of Researchers questioning the official account of 9/11 have proposed alternative theories and explanations about the events surrounding September 11th. ... There were isolated cases of commercial opportunism following the September 11, 2001 attacks and subsequent 2001 anthrax attacks. ... The Joint Inquiry into Intelligence Community Activities before and after the Terrorist Attacks of September 11, 2001 is the official name of the inquiry conducted by the Senate Select Committee on Intelligence and the House Permanent Select Committee on Intelligence into the activities of the U.S. Intelligence Community in... The Commissions seal The National Commission on Terrorist Attacks Upon the United States, also known as the 9/11 Commission, was set up in late 2002 to prepare a full and complete account of the circumstances surrounding the September 11, 2001 attacks including preparedness for and the immediate response... Al-Qaeda (Arabic: القاعدة, the foundation or the base) is the name given to a worldwide network of militant Islamist organizations under the leadership of Osama bin Laden. ... United Airlines Flight 93, a flight aboard a Boeing 757-222, was a flight that regularly flew from Newark International Airport (now known as Newark Liberty International Airport) in Newark, New Jersey, to San Francisco International Airport continuing on to Narita International Airport in Tokyo, Japan, on a different aircraft. ...

20th hijackers

The 9/11 Commission concluded that eight members of al-Qaeda, in addition to the nineteen hijackers, attempted to enter the United States to participate in the attacks. The National Commission on Terrorist Attacks Upon the United States, also known as the 9/11 Commission, was set up in late 2002 to prepare a full and complete account of the circumstances surrounding the September 11, 2001 attacks including preparedness for and the immediate response to the attacks. ...

Ramzi Binalshibh was repeatedly denied entry into the U.S and was unable to take part. Mohamed al-Kahtani was another would-be hijacker, but he was denied entry into the U.S. at Orlando International Airport in August, 2001. He was later captured and imprisoned at Guantanamo Bay. Ramzi Binalshibh (Arabic: رمزي بن الشيبة; also transliterated as Ramzi bin al-Shibh, Ramzi bin al-Shaibah, and several other ways; born 1973), is a citizen of Yemen and according to the United States, Germany, and several other countries, a key al-Qaida member who helped in planning the September... Mohamed Mani Ahmad al-Kahtani (Arabic: sometimes transliterated Muhammed Al Kahtani or other ways) is a member of the terrorist group al-Qaida. ... Orlando International Airport (IATA: MCO, ICAO: KMCO) is an airport located in Orlando, Florida. ... Map of Cuba with location of Guantánamo Bay indicated. ...

Zacarias Moussaoui was considered as a replacement for Ziad Jarrah, who at one point threatened to withdraw from the scheme because of tensions amongst the plotters. Plans to include Moussaoui were never finalized, as the al-Qaeda hierarchy had doubts about his reliability. Ultimately, Moussaoui did not play a role in the hijacking scheme. He was arrested about four weeks before the attacks. Moussaoui mugshot Zacarias Moussaoui (Arabic: زكريا موسوي) (born May 30, 1968) is a French citizen of Moroccan descent who has testified that he was involved in the conspiracy that resulted in the September 11, 2001 attacks. ... Jarrah grew up in a wealthy, secular family Born on May 11, 1975, Ziad Samir Jarrah (Arabic: زياد سمير جراح), was named by the FBI as being the pilot of the hijacked United Airlines Flight 93 as part of the September 11, 2001 attacks. ...

The other al-Qaeda members who attempted to take part in the attacks, but were not able, were Saeed al-Ghamdi (not to be confused with the successful hijacker of the same name), Mushabib al-Hamlan, Zakariyah Essabar, Ali Abdul Aziz Ali and Tawfiq bin Attash. Khalid Sheikh Mohammed, the attack's mastermind, had wanted to remove at least one member — Khalid al-Mihdhar — from the operation, but he was overruled by Osama bin Laden. A original candidate in the September 11, 2001 attack, Mushabib al-Hamlan became involved with militancy at secondary-school in December 1999, where he attended gatherings to watch videos about the glory of Jihad and detailing the atrocities of the Soviet invasion of Afghanistan and the Yugoslav wars. ... Zakariyah Essabar is a known member of al-Qaida Zakariyah Essabar (Arabic: زكريا الصبار) is, according to the governments of the United States, Germany, and other countries, a member of al-Qaida and an associate of many of the organizers of the September 11, 2001 attacks. ... Ali Abdul Aziz Ali (Arabic: علي عبدالعزيز علي) is a member of the al-Qaida terrorist organization and reportedly a nephew or cousin of Khalid Shaikh Mohammed, an important leader in the organization. ... Tawfiq bin Attash, aka Khallad, is an Al Qaeda member of long standing. ... Khalid Shaikh Mohammed (Arabic: خالد شيخ محمد; also transliterated as Khalid Sheikh Mohammed, Khalid Shaikh Mohammad, and other ways) (March 1, 1964 or April 14, 1965 – present) was an important figure in Osama bin Ladens al-Qaeda organization, where he masterminded numerous plans and came to head the group... This photograph of Khalid al-Midhar was released by the FBI in the days following the attack. ... Osama bin Laden in a photo from the 1990s Usāmah bin Muhammad bin Awad bin Lādin (Arabic: ; born March 10, 1957 he is a sick son of a bitch[1]), most commonly known as Osama bin Laden or Usama bin Laden (أسامة بن لادن) is an Islamic fundamentalist, a primary founder...