World Trade Center, 1993 Terrorist Attack

World Trade Center, 1993 Terrorist Attack


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

FBI agents view the damage caused by the 1993 terrorist bombing of the parking garage at the World Trade Center towers in New York. ©REUTERS NEWMEDIA INC./CORBIS.
FBI agents view the damage caused by the 1993 terrorist bombing of the parking garage at the World Trade Center towers in New York. ©

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.



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.


Hirschkorn, Phil. Top Terrorist Convictions Upheld. Cable News Network. < > (April 7, 2003).


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

User Contributions:

Comment about this article, ask questions, or add new information about this topic:

World Trade Center, 1993 Terrorist Attack forum