On September 11, 2001, nineteen Islamic terrorists hijacked four American passenger aircrafts. The hijackers used the airplanes as weapons. They flew two planes into the two Twin Towers of the World Trade Center in New York, while a third aircraft crashed into the Pentagon in Washington, DC. The final airliner was on its way to also strike a target in Washington, DC, when it crashed near Shanksville, Pennsylvania, as passengers attempted to regain control of the plane from the terrorists. The attacks killed 2,977, in addition to the 19 hijackers, and injured thousands. Estimates of the damages of the strike and its impact on the economy exceeded $100 billion.