September 11 attacks
The September 11 attacks (also referred to as 9/11) were a series of four coordinated terrorist attacks by the Islamic terrorist group al-Qaeda against the United States on the morning of Tuesday, September 11, 2001. The attacks killed 2,996 people, injured over 6,000 others, and caused at least $10 billion in infrastructure and property damage. Additional people died of 9/11-related cancer and respiratory diseases in the months and years following the attacks.
Right-wing terrorism
As of December 2018, the New America Foundation placed the number killed in terrorist attacks in the United States since 9/11 as follows: 104 killed in jihadist terrorist attacks, 86 killed in far-right attacks, 8 killed in black separatist/nationalist/supremacist attacks, and 8 killed in ideological misogyny/"incel" ideology attacks. The politically conservative Daily Caller News Foundation using data from the National Consortium for the Study of Terrorism and Responses to Terrorism (START), found 92% of all "ideologically motivated homicide incidents" committed in the United States from 2007 to 2016 were motivated by right-wing extremism or white supremacism. According to the Government Accountability Office of the United States, 73% of violent extremist incidents that resulted in deaths since September 12, 2001 were caused by right-wing extremist groups.