Sunday, September 11, 2016 marks 15 years since the 9/11 attacks on America.
Ceremonies were held at the sites of the attacks at the World Trade Center, Pentagon, and the Flight 93 National Memorial in Pennsylvania.
Here is the order of major events on the day of Tuesday, September 11, 2001 (Times in Eastern Time):
8:46 a.m. - Flight 11 crashes into the north side of the North Tower (1 WTC) of the World Trade Center, between floors 93 and 99, in lower Manhattan.
9:03 - Flight 175 crashes into the south side of the South Tower (2 WTC) of the World Trade Center, between floors 77 and 85, in lower Manhattan.
9:37- Flight 77 into the western side of the Pentagon in Washington D.C.
9:58 - The South Tower of the World Trade Center collapses 56 minutes after the impact of Flight 175.
10:03 - United Airlines Flight 93 is crashed by its hijackers and passengers in Somerset County, Pennsylvania. The suspected targets of Flight 93 were the U.S. Capitol Building or the White House in Washington D.C.
10:28 - The North Tower of the World Trade Center collapses 1 hour and 42 minutes after the impact of Flight 11.
5:20 p.m. - 7 World Trade Center (7 WTC) a 47-story building of the World Trade Center collapses. No one is injured in the collapse as there was enough time to evacuate following the collapse of the North Tower. The building housed the Office of Emergency Management, an agency meant to respond to such events as 9/11.