World Trade Center, 1993 Terrorist Attack

█ JUDSON KNIGHT

The World Trade Center (WTC) bombing of 1993 has long since been overshadowed by the attack that brought the twin towers down on September 11, 2001. Yet, at the time it occurred, the attack loomed as large on the American landscape as the towers themselves once did on the Manhattan skyline. The attack killed six people and injured more than a thousand, the first casualties from foreign terrorists on U.S. soil. American authorities identified at least eight perpetrators, but questions remain as to the ultimate cause of the attack.

The attack and its aftermath. At 12:18 p.m. on Friday, February 26, 1993, an explosion rocked the second level of the parking basement beneath Trade Tower One. The explosive material, as investigators would later determine, was somewhere between 1,200 and 1,500 pounds (544–680 kg) of urea nitrate, a homemade fertilizer-based explosive.

The blast ripped open a crater 150 feet (46 m) in diameter and five floors deep, rupturing sewer and water mains and cutting off electricity. Over the hours that followed, more than 50,000 people were evacuated from the Trade Center complex. A stunned nation soon grasped a fact larger than the incident itself: foreign-sponsored terrorism—which had long plagued Western Europe and parts of the Middle East, Africa, and Asia—had come to the United States.

Investigation and cleanup begins. The first analysis team to arrive came from the Federal Bureau of Investigation (FBI), who soon brought in two examiners from the FBI Laboratory Explosives Unit. Over the week that followed, a team of more than 300 law-enforcement officers from various agencies throughout the country would sift through some 2,500 cubic yards (1,911 cubic meters) of debris weighing more than 6,800 tons (6,909 tonnes).

At the same time that this forensic investigation began, government authorities rushed to protect against physical, chemical, and biological hazards associated with the blast. The explosion had exposed raw sewage, asbestos, mineral wool, acid, and fumes from automobiles. Meanwhile, small electrical fires burned, and pieces of concrete and sharp metal hung threateningly from distended beams.

On Saturday, authorities installed seismographic equipment, cleared the area, and conducted a test run of an empty subway train. The results showed that with a few adjustments, the area could be rendered safe for the operation of the Port Authority Transportation system (PATH) on Monday, thus preventing a virtual shutdown of lower Manhattan. The Environmental Protection Agency and the Occupational Safety and Health Administration began taking steps to clean up biological and chemical debris.

Tracking the killers. Meanwhile, the forensic investigation expanded, with two chemists each from the FBI, ATF (Bureau of Alcohol, Tobacco, and Firearms), and New York Police Department collecting and studying residue from the blast area. In the course of this work, investigators found a key piece of evidence: a 300-pound (136-kg) fragment of a vehicle that, based on the damage it had sustained, must have been at the very epicenter of the blast. Sewage contamination had rendered it unusable for residue analysis, but it bore something much better: a vehicle identification number (VIN).

This was not to be the first fortunate break for investigators. Authorities traced the vehicle to a Ryder truck rental facility in Jersey City, New Jersey, from which it had been reported stolen. On Monday, while FBI special agents were at the Jersey City facility to speak with personnel there, the Ryder clerk received a call from a man identified as Mohamed Salemeh. The latter demanded the return of

his $400 deposit for the van in question, and the Ryder clerk arranged for him to return and collect the deposit on March 4, 1993. When Salemeh arrived, he was arrested.

A search of Salemeh's belongings led investigators to Nidal Ayad, a chemist working for the Allied Signal Corporation in New Jersey. Toll records and receipts helped lead to a safe house in Jersey City, New Jersey, where authorities found traces of nitroglycerine and urea nitrate. They also uncovered evidence that Salemeh and Ayad had obtained three tanks of compressed hydrogen gas, and in the course of searching a storage room rented by Salemeh, investigators found large caches of urea, sulfuric acid, and other chemicals used in making a bomb. On March 3, the New York Times received a letter claiming responsibility for the bombing, and subsequent investigation of DNA samples matched Ayad with the saliva on the envelope flap.

Conviction—and continuing questions. The trail of investigation would eventually lead to Ramzi Yousef, who authorities believe was in the van that delivered the explosives to the WTC. With him was Eyad Ismoil. Also implicated in the bombing, along with Salemeh and Ayad, were Ahmad Ajaj, Mahmoud Abouhalima, and Abdul Rahman Yasin. On March 4, 1994, a jury found Salemeh, Ajaj, Abouhalima, and Ayad guilty on 38 counts, including murder and conspiracy, and the judge handed down multiple life sentences.

Yousef fled the country, and engaged in other terror plots before he was captured and brought to the United States from Pakistan in February 1995. He was sentenced to life plus 240 years. As of 2003, Yasin had not been captured, and was believed to be in Iraq. In October 1995, Sheikh Omar Abdel Rahman, a blind Egyptian cleric who taught at mosques in Brooklyn and New Jersey, was sentenced to life imprisonment for masterminding the attack. But some observers wonder whether the roots of the 1993 WTC attack run much deeper.

The fact that Yousef is the nephew of Khalid Sheikh Mohammed, a top figure in al-Qaeda, suggests a strong connection between the 1993 conspirators and the group who ultimately brought down the towers eight years later. After the September 2001, attack, it was the opinion of many investigators and analysts inside President George W. Bush's administration, that the perpetrators of that attack had a state sponsor—Iraq. A number of details, including the fact that Yousef was traveling on an Iraqi passport, as well as the date of the 1993 attack—the second anniversary of the U.S. liberation of Kuwait in the Persian Gulf War—furthered suspicions of Iraqi involvement in the 1993 incident. Mohammed was later involved in masterminding the terrorist attacks on the World Trade Center in 2001, and was arrested in Rawalpindi, Pakistan on March 1, 2003.

█ FURTHER READING:

BOOKS:

Dwyer, Jim. Two Seconds Under the World: Terror Comes to America. New York: Crown Publishers, 1994.

Gillespie, Angus K. Twin Towers: The Life of New York City's World Trade Center. New Brunswick, NJ: Rutgers University Press, 1999.

Juergensmeyer, Mark. Terror in the Mind of God: The Global Rise of Religious Violence. Berkeley: University of California Press, 2000.

Mylroie, Laurie. Study of Revenge: The First World Trade Center Attack and Saddam Hussein's War against America. Washington, D.C.: AEI Press, 2001.

Reeve, Simon. The New Jackals: Ramzi Yousef, Osama bin Laden, and the Future of Terrorism. Boston: Northeastern University Press, 1999.

ELECTRONIC:

Hirschkorn, Phil. Top Terrorist Convictions Upheld. Cable News Network. <http://www.cnn.com/2003/LAW/04/04/terrorism.yousef/> (April 7, 2003).

SEE ALSO

Bomb Damage, Forensic Assessment
Clinton Administration (1993–2001), United States National Security Policy
United States, Counter-terrorism Policy
Terrorist and Para-State Organizations
World Trade Center, 2001 Terrorist Attack

World Trade Center former building complex in lower Manhattan, New York City, consisting of seven buildings and a shopping concourse on a 16-acre (6.5-hectare) site; it was destroyed by a terrorist attack on Sept. 11, 2001. Prior to its destruction, the World Trade Center had been the world's largest commercial complex, home to many businesses, government agencies, and international trade organizations. Most prominent among its structures were the 110-story rectangular twin towers, one rising to 1,362 ft (415 m) and the other to 1,368 ft (417 m), with floors roughly an acre in size. Designed by Minoru Yamasaki and Emery Roth, the towers and concourse portion of the center were completed in 1973 at a cost of some $750 million. For a brief period (until the completion of the Sears Tower, now the Willis Tower , in Chicago in 1974), the World Trade towers were the tallest buildings in the world. They remained the largest structures on the Eastern Seaboard of the United States, an internationally known landmark and tourist attraction rising high above the skyline of lower Manhattan.

In 1993 a terrorist car-bomb explosion damaged portions of the complex, killing six people and causing more than $300 million in damage. Sheik Omar Abdel Rahman and nine other Islamic extremists were convicted of conspiracy and other charges related to the bombing in 1993, and the so-called mastermind, Ramzi Yousef, was convicted in 1998. On Sept. 11, 2001, a second terrorist attack, in which two hijacked commercial jetliners were crashed into the towers, ignited huge, intense fires in the upper stories of both buildings, weakening them and leading to their collapse. Other structures in the complex were completely or partially destroyed as a result, and many surrounding buildings were severely damaged. More than 2,700 people, including the passengers and crew of the airliners and several hundred emergency personnel responding to the initial fires, lost their lives; more than 7,000 people were injured.

The enormity of the events of Sept. 11 (see also 9/11 ), which also involved a similar attack with a hijacked jetliner on the Pentagon in Washington, D.C., and the crash in W Pennsylvania of a fourth hijacked plane, galvanized national feeling in the United States, where many watched the events unfold on television. In the aftermath of the worst terrorist attack in history, President George W. Bush announced a war on terrorism , and many nations pledged their support. Al Qaeda, headed by Osama bin Laden , was identified by U.S. authorities as being behind the attacks, and the United States subsequently began military operations in Afghanistan, where bin Laden was based and where the government was closely allied with him.

In Dec., 2001, Zacarias Moussaoui, a Frenchman of Moroccan descent who had been arrested (Aug., 2001) on immigration violations in Minnesota, was indicted on charges that he was part of the conspiracy responsible for the September attacks. He pleaded guilty in 2005 to being part of a conspiracy to attack the White House in a similar manner but denied being part of either Sept. 11 attack, and was given a life sentence in 2006.

The alleged mastermind of the plot was Khalid Sheikh Mohammed, a Kuwaiti of Pakistani parentage who had become a high-ranking member of Al Qaeda. He was captured in Pakistan in 2003, held by the United States at an undisclosed location, and transferred to Guantánamo Bay in 2006. According to a censored transcript of a closed-door hearing in 2007, he admitted to organizing and supervising the execution of the attacks of Sept. 11, but the government also later revealed that he had been subjected to waterboarding, which is generally regarded as a form of torture. In Feb., 2008, the Pentagon announced that a military tribunal would try Mohammed and five others held at Guantánamo on conspiracy and other charges relating to the attacks; later plans (2010) for a federal trial were abandoned in 2011 in the face of strong political opposition. Bin Laden, who had approved the attacks and eluded capture by U.S. forces in Afghanistan in the months following the attacks, was killed in May, 2011, during a raid by U.S. forces on the house in Abbottabad, Pakistan, in which he was living in hiding.

In the aftermath of the center's destruction, many competing interests—the city and state of New York, the owners of the site, the buildings' developer, survivors of the attack and families and friends of those killed, and others—advocated a variety of approaches to rebuilding the site. After a lengthy design competition, a preliminary master construction plan for the site, by Daniel Libeskind , was approved in 2003. The design has since been much modified, and a new overall plan was unveiled in 2006.

Embracing the ground where the towers stood is a tree-filled street-level plaza that opened in 2011. The towers' footprints are the focus of the memorial; waterfalls stream over sunken black granite walls that edge square voids, feeding two pools below whose centers are smaller, echoing voids; the names of those who died are cut into bronze panels that surround the pools. The plaza was designed by Peter Walker; the memorial by Michael Arad. The plaza also contains the trapezoidal entrance to an underground museum. Surrounding the memorial will be a group of office towers that rise in height toward the the "Freedom Tower" (Tower 1), designed by the American architect David M. Childs of Skidmore, Owings and Merrill . Tower 2 is being designed by England's Lord Norman Foster , Tower 3 by another English architect, Lord Richard Rogers , and Tower 4 by Japan's Fumihiko Maki. The complex will include as well a transportation hub by Spain's Santiago Calatrava and a performing arts center created by Frank Gehry .

Bibliography: See studies by E. Darton (1999), A. K. Gillespie (1999), W. Langewiesche (2002), and J. Glanz and E. Lipton (2003).

World Trade Center, 1993 Terrorist Attack

The World Trade Center (WTC) bombing of 1993 has since been overshadowed by the attack that brought the twin towers down on September 11, 2001. Yet, at the time it occurred, the attack loomed as large on the American landscape as the towers themselves once did on the Manhattan skyline. The attack killed six people and injured more than one thousand.

The law enforcement response to the tragedy involved a massive forensic investigation designed to determine the cause of the blast, the identities of those responsible and, ultimately, to ascertain why, although Trade Tower One sustained a great deal of damage, it did not collapse. The forensic sleuthing involved the detailed examination of the blast scene, physical and chemical analyses of samples, and forensic accounting to trace a paper trail that led to the suspects.

At 12:18 p.m. on Friday, February 26, 1993, an explosion rocked the second level of the parking basement beneath Trade Tower One. The explosive material, as forensic investigators would later determine in their chemical analyses of samples retrieved at the site, was somewhere between 1,200 and 1,500 pounds (544–680 kg) of urea nitrate, a homemade fertilizer-based explosive.

The blast ripped open a crater 150 feet (46 meters) in diameter and 5 floors deep, rupturing sewer and water mains and cutting off electricity. Over the hours that followed, more than 50,000 people were evacuated from the Trade Center complex.

The first forensic analysis team to arrive was from the Federal Bureau of Investigation (FBI ). The bureau brought in two examiners from the FBI Laboratory Explosives Unit. Over the week that followed, a team of more than 300 law-enforcement officers (including forensic specialists) from various agencies throughout the country would sift through some 2,500 cubic yards of debris weighing more than 6,800 tons.

At the same time that this forensic investigation began, government authorities rushed to protect against physical, chemical, and biological hazards associated with the blast. The explosion had exposed raw sewage, asbestos, mineral wool, acid, and fumes from automobiles. Meanwhile, small electrical fires burned, and pieces of concrete and sharp metal hung threateningly from distended beams.

On Saturday, authorities installed seismographic equipment, cleared the area, and conducted a test run of an empty subway train. The results showed that with a few adjustments, the area could be rendered safe for the operation of the Port Authority Transportation system (PATH) on Monday, thus preventing a virtual shutdown of lower Manhattan. The Environmental Protection Agency and the Occupational Safety and Health Administration began taking steps to clean up biological and chemical debris.

Meanwhile, the forensic investigation expanded, with two chemists each from the FBI, ATF (Bureau of Alcohol, Tobacco, and Firearms), and the New York Police Department collecting and studying residue from the blast area. In the course of this work, investigators found a key piece of evidence : a 300-pound (136-kg) fragment of a vehicle that, based on the damage it had sustained, must have been at the epicenter of the blast. Sewage contamination had rendered it unusable for residue analysis, but recovery of a vehicle identification number allowed the vehicle to be traced.

Authorities traced the vehicle to a Ryder truck rental facility in Jersey City, New Jersey, where it had been reported stolen. On Monday, while FBI special agents were at the Jersey City facility to interview personnel there, a Ryder clerk received a call from a man identified as Mohammed Salameh. The latter demanded the return of his $400 deposit for the van in question, and the Ryder clerk arranged for him to return and collect the deposit on March 4, 1993. When Salameh arrived, he was arrested.

A search of Salameh's belongings led investigators to Nidal Ayyad, a chemist working for the Allied Signal Corporation in New Jersey. Forensic accounting of toll records and receipts helped lead to a safe house in Jersey City, New Jersey, where authorities found traces of nitroglycerine and urea nitrate. They also uncovered evidence that Salameh and Ayyad had obtained three tanks of compressed hydrogen gas. In the course of searching a storage room rented by Salameh, investigators found large caches of urea, sulfuric acid, and other chemicals commonly used in making bombs. On March 3, the New York Times received a letter that claimed responsibility for the bombing. A subsequent forensic investigation of DNA samples matched Ayyad with the saliva on the envelope flap.

A forensic investigation was conducted to examine how such a massive blast failed to collapse the tower. The consensus opinion is that the location of the explosion, on the second level of the underground parking lot, acted to diffuse the intensity of the explosion. When the concrete floor of that level ruptured, much of the force of the blast was directed downward into the lower levels of the parking garage.

see also Architecture and structural analysis; Bomb (explosion) investigations; Bomb damage, forensic assessment; Explosives; September 11, 2001, terrorist attacks (forensic investigations of).

WORLD TRADE CENTER

WORLD TRADE CENTER, a seven-building complex that was located on a sixteen-acre site in lower Manhattan in New York City. The Port Authority of New York and New Jersey financed the $958 million cost of construction. The architect Minoru Yamasaki designed the two 110-story towers (numbers 1 and 2 World Trade) in the International Style; the Twin Towers, as they were called, were to be the tallest buildings in the world, a record they held in 1973. To achieve that height, the engineering firm of Worthington-Skilling recommended a tube structure in which columns on the exterior walls, and the inner core of the skyscrapers, bore the gravity load. A grill of lightweight steel trusses connecting the perimeter and core supported the floors. Given the proximity of the Twin Towers to two major airports, each tower was built to withstand the impact of a Boeing 707 aircraft.

Relying on the perimeter and core columns to provide vertical support created 10 million square feet of open commercial space, which was leased to import and export businesses, government agencies, financial firms, and restaurants. Groundbreaking occurred in 1966; tenants moved into the World Trade Center in December 1970. The last building in the complex, 7 World Trade, a forty-seven story building, was completed in 1985.

On 23 February 1993, a truck bomb tore through an underground parking garage beneath the Vista Hotel (3 World Trade), killing six people. The explosion produced a crater six stories deep and destroyed lateral supports throughout the damaged area. As a result of the bombing, building modifications were introduced to improve evacuation, with tenants receiving evacuation training, and additional

fire command centers were established in the lobbies of the Twin Towers. On 11 September 2001, two hijacked Boeing 767 commercial airliners were flown into the Twin Towers, causing the collapse of both skyscrapers; 2,830 people, including 403 emergency personnel, died.

The Federal Emergency Management Agency (FEMA) led the effort in trying to determine the progression of the collapse, a task complicated by the removal of the beams to recycling centers and scrapyards during the recovery effort. The prevailing hypothesis is that the impact of the airliners sheared off the fireproofing on the trusses, which softened in the subsequent blaze; jet fuel pouring into the elevator shafts spread the fires to lower decks. With the integrity of the sagging floors compromised, it is believed that an unsupportable gravity load was redistributed to the core columns, leading to total structural failure. The damage of the initial impact was also being assessed.

Eight surrounding buildings either partially or totally collapsed that day, crushed by falling debris (3 World Trade) or gutted by fire (7 World Trade). Discussions about the future use of the site, referred to as "Ground Zero"—whether it should be dedicated solely as a memorial or reopened for mixed-use purposes—were ongoing at the end of 2002.

BIBLIOGRAPHY

Federal Emergency Management Agency. World Trade Center Building Performance Study: Data Collection, Preliminary Observations, and Recommendations. New York: Greenhorne and O'Mara, 2002.

Gillespie, Angus Kress. Twin Towers: The Life of New York City's World Trade Center. New Brunswick, N.J.: Rutgers University Press, 1999.

Seabrook, John. "The Tower Builder." New Yorker (19 Nov. 2001): 64–73.

Tristan HopeKirvin

See alsoNew York City ; 9/11 Attack .