Pennsylvania

Marking 15 years since 9/11, ceremony keeps personal focus

  • FILE- In this Sept. 11, 2015 file photo, a woman holds up a photograph during the ceremony commemorating the Sept. 11, 2001 terrorist attacks at the World Trade Center site in New York. Victims' relatives and dignitaries will once again convene Sunday, Sept. 11, 2016, on the memorial plaza at the World Trade Center for one of the constants in how America remembers 9/11 after 15 years, the anniversary ceremony itself. (AP Photo/Bryan R. Smith, File)

    FILE- In this Sept. 11, 2015 file photo, a woman holds up a photograph during the ceremony commemorating the Sept. 11, 2001 terrorist attacks at the World Trade Center site in New York. Victims' relatives and dignitaries will once again convene Sunday, Sept. 11, 2016, on the memorial plaza at the World Trade Center for one of the constants in how America remembers 9/11 after 15 years, the anniversary ceremony itself. (AP Photo/Bryan R. Smith, File)  (The Associated Press)

  • FILE- In this Sept. 11, 2015 file photo, a visitor pauses at the Wall of Names after a Service of Remembrance at the Flight 93 National Memorial in Shanksville, Pa. Victims' relatives and dignitaries will convene Sunday, Sept. 11, 2016, at the site for one of the constants in how America remembers 9/11 after 15 years, the anniversary ceremony itself. (AP Photo/Gene J. Puskar, File)

    FILE- In this Sept. 11, 2015 file photo, a visitor pauses at the Wall of Names after a Service of Remembrance at the Flight 93 National Memorial in Shanksville, Pa. Victims' relatives and dignitaries will convene Sunday, Sept. 11, 2016, at the site for one of the constants in how America remembers 9/11 after 15 years, the anniversary ceremony itself. (AP Photo/Gene J. Puskar, File)  (The Associated Press)

  • FILE- In this Sept. 11, 2015 file photo, a woman wearing a pin in remembrance of Johnnie Doctor, Jr., visits the Pentagon Memorial on the 14th anniversary of the September 11th attacks. Victims' relatives and dignitaries will convene Sunday, Sept. 11, 2016, at the memorial for one of the constants in how America remembers 9/11 after 15 years, the anniversary ceremony itself. (AP Photo/Jacquelyn Martin, File)

    FILE- In this Sept. 11, 2015 file photo, a woman wearing a pin in remembrance of Johnnie Doctor, Jr., visits the Pentagon Memorial on the 14th anniversary of the September 11th attacks. Victims' relatives and dignitaries will convene Sunday, Sept. 11, 2016, at the memorial for one of the constants in how America remembers 9/11 after 15 years, the anniversary ceremony itself. (AP Photo/Jacquelyn Martin, File)  (The Associated Press)

Relatives and loved ones of 9/11 victims will convene Sunday to mark the 15th anniversary of the terror attacks.

Organizers have planned some additional music and readings to mark the milestone anniversary at ground zero.

But they are keeping traditions that have made the ceremony a constant in how America remembers Sept. 11, even as ground zero and the nation changes.

The customs include moments of silence and tolling bells, an apolitical atmosphere and the reading of the nearly 3,000 names of those killed in New York, at the Pentagon and near Shanksville, Pennsylvania.

President Barack Obama will speak at an observance at the Pentagon. Hundreds of people also are expected at a ceremony at the Flight 93 National Memorial in Shanksville.