PENTTBOM (sometimes referred to as PENTTBOMB) is the

codename A code name, codename, call sign, or cryptonym is a code word or name used, sometimes clandestinely, to refer to another name, word, project, or person. Code names are often used for military purposes, or in espionage. They may also be used in ...

for the

Federal Bureau of Investigation The Federal Bureau of Investigation (FBI) is the domestic Intelligence agency, intelligence and Security agency, security service of the United States and Federal law enforcement in the United States, its principal federal law enforcement ag ...

's probe into the

September 11 attacks The September 11 attacks, also known as 9/11, were four coordinated Islamist terrorist suicide attacks by al-Qaeda against the United States in 2001. Nineteen terrorists hijacked four commercial airliners, crashing the first two into ...

of 2001, the largest criminal inquiry in the FBI's history. Its name stands for "

Pentagon In geometry, a pentagon () is any five-sided polygon or 5-gon. The sum of the internal angles in a simple polygon, simple pentagon is 540°. A pentagon may be simple or list of self-intersecting polygons, self-intersecting. A self-intersecting ...

Twin Towers Twins are two offspring produced by the same pregnancy.MedicineNet > Definition of Twin Last Editorial Review: 19 June 2000 Twins can be either ''monozygotic'' ('identical'), meaning that they develop from one zygote, which splits and forms two e ...

Bombing Investigation". The investigation was launched on September 11, 2001, and involved 4,000

special agent In the United States, a special agent is an official title used to refer to certain investigators or detectives of federal, military, tribal, or state agencies who primarily serve in criminal investigatory positions. Additionally, some special ...

s and 3,000 professional employees.

Identifying the hijackers

The FBI was able to identify the 19 hijackers within a matter of days as few suspects made any effort to conceal their names on flight, credit card, and other records.

Identical letters

Three of the hijackers carried copies of an identical handwritten letter (in

Arabic Arabic (, , or , ) is a Central Semitic languages, Central Semitic language of the Afroasiatic languages, Afroasiatic language family spoken primarily in the Arab world. The International Organization for Standardization (ISO) assigns lang ...

) that was found in three separate locations: the first, in a suitcase of hijacker

Mohamed Atta Mohamed Atta (1 September 196811 September 2001) was an Egyptian terrorist hijacker for al-Qaeda. Ideologically a Pan-Islamism, pan-Islamist, he was the ringleader of the September 11 attacks and served as the Aircraft hijacking, hijacker-pi ...

that did not make the connection to

American Airlines Flight 11 American Airlines Flight 11 was a domestic Airline, passenger flight that was hijacked by five al-Qaeda terrorists on the morning of September 11, 2001, as part of the September 11 attacks. The hijacked airliner was deliberately crashed into ...

that crashed into the North Tower of the World Trade Center; the second, in a vehicle parked at

Washington Dulles International Airport Washington Dulles International Airport ( ) – commonly known by its former name of Dulles International Airport, by its airport code of IAD, or simply as Dulles Airport – is an international airport in the Eastern United States, located w ...

that belonged to hijacker

Nawaf al-Hazmi Nawaf Muhammad Salim al-Hazmi (; 9 August 1976 – 11 September 2001)''9/11 Commission Report'', 9/11 Commission, p. 166 was a Saudi terrorist hijacker who was one of five Organizers of the September 11 attacks, hijackers of American Airlines Fli ...

; and the third at the crash site of

United Airlines Flight 93 United Airlines Flight 93 was a domestic scheduled passenger flight that was hijacked by four al-Qaeda terrorists on the morning of September 11, 2001, as part of the September 11 attacks. The hijackers planned to crash the plane into a feder ...

in Shanksville,

Pennsylvania Pennsylvania, officially the Commonwealth of Pennsylvania, is a U.S. state, state spanning the Mid-Atlantic (United States), Mid-Atlantic, Northeastern United States, Northeastern, Appalachian, and Great Lakes region, Great Lakes regions o ...

. According to the testimony before the House Intelligence Subcommittee on Terrorism and Homeland Defense on October 3, 2001, given by J. T. Caruso, the Deputy Assistant Director of the FBI's Counterterrorism Division, "translations of the letter indicate an alarming willingness to die on the part of the hijackers."

Passports recovered

According to testimony by Susan Ginsberg, a staff member of the National Commission on Terrorist attacks upon the United States, in the January 26, 2004, Public Hearing:

WTC site

The passport of hijacker Satam al-Suqami was found a few blocks from the World Trade Center.

Flight 93

According to the

9/11 Commission The National Commission on Terrorist Attacks Upon the United States, commonly known as the 9/11 Commission, was set up on November 27, 2002, to investigate all aspects of the September 11 attacks, the deadliest terrorist attack in world history ...

, the passports of two of the Flight 93 hijackers were also found intact in the aircraft's debris field.

Atta's luggage

The doctored passport of hijacker Abdulaziz al-Omari was found in Mohamed Atta's left-behind luggage. When examining

's luggage, the FBI found important clues about the hijackers and their plans. His luggage contained papers that revealed the identity of all 19 hijackers, and provided information about their plans, motives, and backgrounds. The FBI was able to determine details such as dates of birth, known and/or possible residences, visa statuses, and specific identities of the suspected pilots.

Recovery of remains

Linking the hijackers to al-Qaeda

The investigators were quickly able to link the 19 men to the terrorist organization

al-Qaeda , image = Flag of Jihad.svg , caption = Jihadist flag, Flag used by various al-Qaeda factions , founder = Osama bin Laden{{Assassinated, Killing of Osama bin Laden , leaders = {{Plainlist, * Osama bin Lad ...

, by accessing their intelligence agency files. ''

The New York Times ''The New York Times'' (''NYT'') is an American daily newspaper based in New York City. ''The New York Times'' covers domestic, national, and international news, and publishes opinion pieces, investigative reports, and reviews. As one of ...

'' reported on September 12 that: "Authorities said they had also identified accomplices in several cities who had helped plan and execute Tuesday's attacks. Officials said they knew who these people were and important biographical details about many of them. They prepared biographies of each identified member of the hijack teams, and began tracing the recent movements of the men." FBI agents in Florida investigating the hijackers quickly "descended on flight schools, neighborhoods and restaurants in pursuit of leads." At one flight school, "students said investigators were there within hours of Tuesday's attacks." ''

The Washington Post ''The Washington Post'', locally known as ''The'' ''Post'' and, informally, ''WaPo'' or ''WP'', is an American daily newspaper published in Washington, D.C., the national capital. It is the most widely circulated newspaper in the Washington m ...

'' later reported that "In the hours after Tuesday's bombings, investigators searched their files on atamAl Suqami and hmedAlghamdi, noted the pair's ties to abilal-Marabh and launched a hunt for him." On September 27, 2001, the FBI released photos of the 19 hijackers, along with information about the possible nationalities and aliases of many. On the day of the attacks, U.S.

intelligence Intelligence has been defined in many ways: the capacity for abstraction, logic, understanding, self-awareness, learning, emotional knowledge, reasoning, planning, creativity, critical thinking, and problem-solving. It can be described as t ...

agencies also intercepted communications that pointed to

Osama bin Laden Osama bin Laden (10 March 19572 May 2011) was a militant leader who was the founder and first general emir of al-Qaeda. Ideologically a pan-Islamist, Bin Laden participated in the Afghan ''mujahideen'' against the Soviet Union, and support ...

. It was quickly asserted that Osama bin Laden was responsible for the attacks, and other suspects were ruled out. Although he denied the attacks at first, Osama bin Laden later admitted full and sole responsibility for the attacks in a video tape.

Press releases

*September 11, 2001: FBI opens investigations *September 14: FBI releases list of 9/11 hijacker suspects *September 27: FBI releases photographs of 9/11 hijacker suspects *September 28: FBI releases four-page letter believed to be written by the hijackers *October 4: FBI releases partial timeline for

Boston Boston is the capital and most populous city in the Commonwealth (U.S. state), Commonwealth of Massachusetts in the United States. The city serves as the cultural and Financial centre, financial center of New England, a region of the Northeas ...

-based hijackers

References

External links

FBI's 9/11 Team Still Hard at Work
from ''

'' June 14, 2004
FBI PENTTBOM suspects

PENTTBOM timeline
{{DEFAULTSORT:Penttbom Federal Bureau of Investigation operations Proceedings surrounding the September 11 attacks