City authorities and the Federal Bureau of Investigation (FBI) undertook a massive manhunt for suspects, and within days several radical Islamic fundamentalists were arrested. In March 1994, Mohammed Salameh, Ahmad Ajaj, Nidal Ayyad, and Mahmoud Abouhalima were convicted by a federal jury for their role in the bombing, and each was sentenced to life in prison. Salameh, a Palestinian, was arrested when he went to retrieve the $400 deposit he had left for the Ryder rental van used in the attack. Ajaj and Ayyad, who both played a role in the construction of the bomb, were arrested soon after. Abouhalima, who helped buy and mix the explosives, fled to Saudi Arabia but was caught in Egypt two weeks later.
The mastermind of the attack—Ramzi Ahmed Yousef—remained at large until February 1995, when he was arrested in Pakistan. He had previously been in the Philippines, and in a computer he left there were found terrorist plans that included a plot to kill Pope John Paul II and a plan to bomb 15 American airliners in 48 hours. On the flight back to the United States, Yousef reportedly admitted to a Secret Service agent that he had directed the Trade Center attack from the beginning and even claimed to have set the fuse that exploded the 1,200-pound bomb. His only regret, the agent quoted Yousef saying, was that the 110-story tower did not collapse into its twin as planned—a catastrophe that would have caused thousands of deaths.
Eyad Ismoil, who drove the Ryder van into the parking garage below the World Trade Center, was captured in Jordan that year and taken back to New York. All the men implicated had ties to Sheik Omar Abdel Rahman, a radical Egyptian religious leader who operated out of Jersey City, New Jersey, located just across the Hudson River from Manhattan. In 1995, Rahman and 10 followers were convicted of conspiring to blow up the United Nations headquarters and other New York landmarks. Prosecutors argued that the World Trade Center attack was part of that conspiracy, though little clear evidence of this charge was presented.
In November 1997, Yousef and Ismoil were convicted in a courtroom only a few blocks away from the twin towers and subsequently sentenced to life in prison without the possibility of parole. Only one other man believed to be directly involved in the attack, Iraqi Abdul Rahman Yasin, remains at large.
After the 1998 bombings of U.S. embassies in Kenya and Tanzania, U.S. investigators began to suspect that Yousef had ties to Saudi exile Osama bin Laden, the head of the anti-U.S. al Qaeda terrorist network. Whether bin Laden was in fact involved in the 1993 Twin Tower attacks has not been determined, but on September 11, 2001, two groups of al Qaeda terrorists finished the job begun by Yousef, crashing two hijacked airliners into the north and south tower of the World Trade Center.
The structural steel of the skyscrapers could not withstand the tremendous heat generated by the burning jet fuel, and both collapsed within two hours of being struck. Close to 3,000 people died in the World Trade Center and its vicinity, including a staggering 343 firefighters and 23 policemen who were struggling to complete the evacuation and save the office workers trapped on higher floors. Only six people in the World Trade Center towers at the time of their collapse survived. Almost 10,000 other people were treated for injuries, many severe.
