As per reports, Yousef flew into the U.S. six months before the February 1993 bombing. He arrived with a fake Iraqi passport, requested political asylum and took up with a handful of Muslim extremists in New Jersey. Then he started ordering chemicals to make a bomb.
Yousef ordered 1,000 pounds (454 kgs) of urea and 100 gallons (378.5 liters) of nitric acid which, when mixed together "makes a powerful explosion." He later ordered hydrogen "which gave the bomb an extra kick."
Then he called Ismoil, a childhood friend from Kuwait who was living in Dallas, to come help drive the bomb in a rental van into the Trade Center garage.
