In which year, terrorists crash two planes into New York's World Trade Centre on September 11 in a sequence of destruction?

In year 2001, terrorists crash two planes into New York's World Trade Centre on September 11 in a sequence of destruction. The September 11 attacks were a series of airline hijackings and suicide attacks committed in 2001 by 19 terrorists associated with the Islamic extremist group al-Qaeda. It was the deadliest terrorist attack on U.S. soil; nearly 3,000 people were killed.