The world watched on in horror as two hijacked planes crashed into the twin towers of the world trade centre on September 11, 2001. American Airlines Boeing 767 crashed into the north tower first, killing hundreds of people instantly and trapping hundreds above the 80th floor. Exactly 18 minutes later, a second plane crashed into the south tower. Following this, an additional plane crashed into the west side of the Pentagon. The attackers were militants associated with the Islamic extremist group Al-Qaeda reportedly seeking revenge for America's support of Israel, as well as its role in the Persian Gulf War and its military presence in the Middle East. Over 3,000 people were killed in the terror attacks of September 11th, 2001, among those over 400 firefighters and police officers.