Twenty years ago, a small group of radical Muslim terrorists attacked the United States by hijacking four commercial flights and flying three of the jumbo jets, filled with ordinary passengers, into large buildings in New York and Washington DC. The fourth flight, whose quick-thinking passengers foiled terrorists’ mission, crashed in a Pennsylvania field. Over 3,000 people died that day.

This short video of live footage and clips of actual events on 9-11-2001 serves as a reminder of the chilling events as they unfolded: