India, Sept. 8 -- For three decades, the Twin Towers were among the most recognisable structures, not only in New York but in the world. They rose above Lower Manhattan and became a symbol of the city.

This, though, also made them a target. Eight years before the September 11, 2001 attack, attackers had already tried to destroy the World Trade Center.

The Twin Towers were the two landmark 110-story skyscrapers, whereas the WTC was the entire multi-building business complex that contained them.

On February 26, 1993, a van packed with explosives was driven into the public parking garage beneath the North Tower. The bomb exploded shortly after noon. It did not bring down the towers but killed several people.

As the first major terrorist ...