- 2,977 people died in the attacks of September 11, 2001
- The first moment of silence will be at 8:46 a.m., the time of the first attack
The age of terror had begun.
"September 11, 2001, touched every single one of us," New York City Mayor Bill de Blasio said Saturday during a memorial service at St. Patrick's Cathedral for the city's fire department. "There is no New Yorker who somehow evaded the pain of that day. We all felt it. We all were affected. Everyone felt it. Everyone suffered."
The 2,977 men and women who died in the attacks are being remembered this weekend with parades and memorials throughout the country. Special services will be held at the spots where the planes crashed.
At Ground Zero, where the towers stood, the first moment of silence will be observed at 8:46 a.m. ET -- the time the first plane hit the North Tower.
Houses of worship throughout New York City will toll their bells and families of victims of the 2001 attacks -- as well as the 1993 bombing at the World Trade Center -- will read the names of the people killed. A livestream of this event can be seen at www.911memorial.org.
Presidential candidates Hillary Clinton and Donald Trump are expected to visit Ground Zero on Sunday.
In Washington, President Barack Obama, Defense Secretary Ash Carter and Joint Chiefs of Staff Chairman Marine Corps Gen. Joe Dunford will address the families and friends of the 9/11 victims in a ceremony at the Pentagon Memorial.
The ceremony can be watched live on the Department of Defense website.
A moment of silence will be held at the White House at 8:46 a.m. and the Pentagon ceremony starts at 9:30 a.m.
One of the hijacked planes crashed outside Shanksville, Pennsylvania
, apparently forced down by the terrorists short of their intended target after the passengers and crew fought back. A service will be held at the Flight 93 National Memorial starting at 9:45 a.m. ET Sunday.