Ther are 2 answers to this question. 1) The World Trade Center buildings were a physical sign of America power in the world. al-Qeada is very much into destroying icons of power - they want to return...
No, airline planes were flown directly at it to cause their downfall. A bomb blowing up the twin towers is just a theory. The planes crashing into the towers actually happened.
Terrorists. Three planes were stolen from an American Airlines and were later used to kill many people. On September 11, 2001, one plane that had been hijacked flew into the Twin Towers. Many people...