9/11 - Flight 93

There are many different theories as to what really happened on September 11th 2001. Nobody knows what happened but everyone has an opinion. There is only two things we can know for definite:
1: The world will forever mourn the deaths of those killed on that tragic day.
2: We will never know the true story of the attack and the events that followed as a result.

The attacks on September 11th 2001 or 9/11 were a series of 4 terrorist attacks launched by the Isalmist group al-Qaeda upon the United States in Washington DC and New York.
    Four passenger airlines were hijacked by 19 al-Qaeda so that they could be flown into bulidings in devestating suicide attacks. Two of the planes were flown into the North and South towers of the World Trade Centre in New York City. A third plane was crashed into the Pentagon in Washinton DC (the headquarters of the United States Department of Defence.) The fourth plane was targeted at Washington DC but crashed into a field near Shanksville, Pennsylvania after its passengers tried to overcome the hijackers...apparently!
    In total almost 3000 people died in the attacks. Suspision quickly fell on al-Qaeda and, although the groups leader, Osama Bin Laden, initially denied any involvement in the attacks, in 2004, he claimed responsibility

THE THEORIES!!!!
Apparently, the passengers of United Airlines flight 93 teamed up in order to overthrow the hijackers and their plans to crash into the White House, and, it was their heroic attempts that resulted in the plane crashing into a field in Pennsylvania. However,

But conspiracy theorists believe  Flight 93 was destroyed by a heat-seeking missile from a mysterious white plane. At least 6 eye witnesses say that they saw a small white jet flying low over the crash area almost immediately after Flight 93 went down. It is believed that the aircraft was either taken out by a missile fired from an Air Force jet, or via an electronic assault made by a US Customs airplane reorted to have been seen near the site minutes after Flight 93 crashed. Shortly after, the FBI began attacking the witnesses with perhaps the most impossible disinformation ever - alleging the witnesses actually observed a private jet at 34,000 feet. The FBI says the jet was asked to come down to 5000 feet in order to try and find the crash site. This would require about 20 minutes to descend (therefore contradicting everything the numerous eye witnesses reported.) Flight 93 was apparently shot down to prevent it from getting any closer to Washington DC.  In the end, Flight 93 was only 15.6 minutes away at 500mph speeds from D.C when it crashed.