Twin Towers, the BrE AmE
two very tall ↑ skyscraper s that were part of the World Trade Center, a group of buildings in Manhattan, New York City. When they were built in the 1970s, the towers were the tallest in the world. In 1993 ↑ terrorist s killed six people with a bomb they had left there. On 11 September 2001, terrorists flew two planes filled with passengers into the Twin Towers which caused them to fall down. Almost 3000 people were killed, including everyone on the planes and many ↑ firefighter s and police officers who were trying to save people in the buildings. It is believed that the terrorist organization al-Qaeda was responsible for the attack.