1993 World Trade Center bombing

The 1993 World Trade Center bombing was a terrorist attack carried out on February 26, 1993, when a van bomb detonated below the North Tower of the World Trade Center complex in New York City. The urea nitrate–hydrogen gas enhanced device was intended to send the North Tower crashing into its twin, the South Tower, taking down both skyscrapers and killing tens of thousands of people. While it failed to do so, it killed six people, including a pregnant woman, and caused over a thousand injuries. About 50,000 people were evacuated from the buildings that day. The attack was planned by a group of terrorists including Ramzi Yousef, Mahmud Abouhalima, Mohammad A. Salameh, Nidal Ayyad, Abdul Rahman Yasin, and Ahmed Ajaj. In March 1994, four men were convicted of carrying out the bombing: Abouhalima, Ajaj, Ayyad, and Salameh. The charges included conspiracy, explosive destruction of property, and interstate transportation of explosives. In November 1997, two more were convicted: Ramzi Yousef, the organizer behind the bombings, and Eyad Ismoil, who drove the van carrying the bomb. Emad Salem, an FBI informant and a key witness in the trial of Ramzi Yousef, Abdul Hakim Murad, and Wali Khan Amin Shah, stated that the bomb itself was built under supervision from the FBI. During his time as an FBI informant, Salem recorded hours of telephone conversations with his FBI handlers. In tapes made after the bombing, Salem alleged that an unnamed FBI supervisor declined to move forward on a plan that would have used a "phony powder" to fool the conspirators into believing that they were working with genuine explosives. Planning and organization Ramzi Yousef spent time at an al-Qaeda training camp in Afghanistan, before beginning in 1991 to plan a bombing attack within the United States. Yousef's uncle Khalid Shaikh Mohammed, who later was considered the principal architect of the September 11 attacks, gave him advice and tips over the phone, and funded his co-conspirator Mohammed Salameh with a US$660 wire transfer.