9-11 was one of the most horrible terrorist attacks on the United States. I believe that it was a horrible act of terror because it truly was. Plotted by Osama Bin Laden and his terrorist group Al qaeda. This was such a shock to everyone in the U.S as they were watching the plane hit the towers and the towers burn. At first people thought that it was just a really bad accident. Then the second plane hit and it became clear that it was an attack. Many people were injured not just physically but emotionally as well. Overall 9-11 will be a day that we will all never forget.