The document describes four significant terrorist attacks and mass shootings that occurred in the United States between 2001 and 2013. It notes that on September 11, 2001, al-Qaeda launched four coordinated attacks using hijacked planes in New York City and Washington D.C., killing thousands. It also mentions that in 2012, a gunman fatally shot 28 people, including 20 children, at Sandy Hook Elementary School in Connecticut. Additionally, the document states that in 2013, a lone gunman shot and killed 12 people at the Washington Navy Yard in Washington D.C.

1. Luis Ramirez

2.  A series of four coordinated terrorist attacks
launched by the Islamic terrorist group al-
 Qaeda upon the United States in New York
City and the Washington, D.C. metropolitan
area on Tuesday, September 11, 2011 and The
fourth plane, United Airlines Flight 93, was
targeted at Washington, D.C., but crashed into
a field near Shanksville, Pennsylvania

3. On June 25, 2009, Michael Jackson died of acute propofol and
benzodiazepine intoxication after suffering a cardiac arrest at his
home on North Carolwood Drive in the Holmby Hills
neighborhood in Los Angeles.

4.  On December 14, 2012, 20-year-old
Adam Lanza fatally shot twenty
children and six adult staff members in
a mass murder at Sandy Hook
Elementary School in the village of
Sandy Hook in Newtown, Connecticut

5.  On September 16, 2013, Aaron Alexis, a lone gunman
armed initially with a shotgun, fatally shot twelve
people and injured three others in a mass shooting at
the headquarters of the Naval Sea Systems Command
(NAVSEA) inside the Washington Navy Yard in
Southeast Washington, D.C