9/11 was one of the biggest terrorist attacks in United States history. This attack happened when a group of al-Qaeda terrorist attacked the World Trade Center in New York and left a giant burning hole in the side of the building. They attacked the World Trade Center with American airline planes filled with 20,000 gallons of jet fuel that they stole. They hijacked four planes two went into the World Trade Center, one went into a field in Pennsylvania, and one flew into the Pentagon. There was a lot of loved people that passed away on that day. We will always remember the firefighters and Police officers that risked their lives to keep this country safe.