9/11
On 11 September 2001, four planes were hijacked by al-Qaeda and two of them were flown into the twin towers of the World Trade Center in New York, killing 2,996 people.
However, some believe that the attack was an inside job, orchestrated in order to cement the US's place as the top global power or to secure the oil reserves in the Middle East.
Article continues belowThe Week
Escape your echo chamber. Get the facts behind the news, plus analysis from multiple perspectives.
Sign up for The Week's Free Newsletters
From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.
From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.
Another theory is that the building's owners were responsible for the event (they stood to gain $500m in insurance profits). For more detail, read our feature on the top ten 9/11 conspiracy theories.