Somber ceremonies mark 9/11 anniversary

Daniel Henry, a Port Authority of New York/New Jersey police officer, pauses during a moment of silence at 9:01 am EDT, at the South Reflecting Pool of the 9/11 Memorial during ceremonies for the twelfth anniversary of the terrorist attacks on lower Manhattan at the World Trade Center site on Sept. 11, 2013.

The nation is commemorating the anniversary of the 2001 attacks which resulted in the deaths of nearly 3,000 people after two hijacked planes crashed into the World Trade Center, one into the Pentagon in Arlington, Va., and one crash landed in Shanksville, Pa.

Following the attacks in New York, the former location of the Twin Towers has been turned into the National September 11 Memorial and Museum.

Read more: 9/11 remembrances take somber tone

Family members of the victims and survivors of the Sept. 11, 2001, attack on the Pentagon wait for the arrival of the official party before an observance ceremony at the Pentagon Sept. 11, 2013, in Arlington, Va.

A Port Authority Police Officer touches the 9/11 Memorial during ceremonies for the twelfth anniversary of the terrorist attacks on lower Manhattan.

Visitors to the Flight 93 National Memorial participate in a sunset ceremony with a giant flag memorializing Flight 93, Sept. 10, 2013.

A family member of the victims of the September 11, 2001, attack on the Pentagon visits the memorial site before an observance ceremony at the Pentagon, Sept. 11, 2013, in Arlington, Va.

A woman gazes at the One World Trade Center as church bells toll for 9/11 victims in New York City.

Secretary of the Interior Sally Jewell, third from left, leads the ground breaking for the Flight 93 National Memorial visitor center complex in Shanksville, Pa., Sept. 10, 2013.

President Barack Obama, first lady Michelle Obama, Vice President Joe Biden, and Jill Biden bow their heads for a moment of silence on the South Lawn of the White House in Washington, Sept. 11, 2013, to mark the 12th anniversary of the September 11 terror attacks.

A photo of New York City Firefighter Robert James Crawford who died of the attacks of September 11, 2001 was placed by his family as they came to participate in ceremonies for the twelfth anniversary of the terrorist attacks on lower Manhattan at the World Trade Center site, Sept. 11, 2013.

Kayla Fallon, daughter of William Fallon who perished in Tower One when she was 8 years old, reacts as she attends ceremonies for the twelfth anniversary of the terrorist attacks on lower Manhattan at the World Trade Center site, Sept. 11, 2013.

People stand at the 9/11 Memorial during ceremonies for the twelfth anniversary of the terrorist attacks on lower Manhattan at the World Trade Center site.

Michelle Murray of Rockaway, N.J. stands at the 9/11 Memorial during ceremonies for the twelfth anniversary of the terrorist attacks on lower Manhattan.

A visitor kisses a name on the memorial wall engraved with the 40 names of the crew and passengers of Flight 93 at the Flight 93 National Memorial during a candlelight remembrance, Sept. 10, 2013.

A woman makes rubbings of a name at the 9/11 Memorial during ceremonies for the twelfth anniversary of the terrorist attacks on lower Manhattan at the World Trade Center site.

Hector Garcia of Brooklyn and his daughter Tania hold a placard with a photo of their daughter and sister Marlyn who died in the attacks as they attend ceremonies for the twelfth anniversary of the terrorist attacks on lower Manhattan at the World Trade Center site.

Family members of Ji Yao Justin Zhao pay their respects at the South Pool of the 9/11 Memorial during ceremonies for the twelfth anniversary of the terrorist attacks on lower Manhattan at the World Trade Center site.

Gail Silke (L) and her niece Erica Tierney trace the name of Gail's brother Steven Bristoll who worked as a police officer at the the 9/11 Memorial during ceremonies for the twelfth anniversary of the terrorist attacks on lower Manhattan.

Steven Campbell pauses to remember his wife Jill Maurer-Campbell during ceremonies for the twelfth anniversary of the terrorist attacks on lower Manhattan at the World Trade Center.

President Barack Obama places a wreath during a memorial service at the National 9/11 Pentagon Memorial in Washington, D.C.

Obama, Secretary of Defense Chuck Hagel and others attended the event to mark the 12th anniversary of terror attacks on the Pentagon, the World Trade Center and Shanksville, Pa.

People visit the 9/11 Memorial during ceremonies for the twelfth anniversary of the terrorist attacks on lower Manhattan at the World Trade Center site.

New Jersey Governor Chris Christie, center, and his wife Mary Pat Christie walk around a memorial waterfall during ceremonies marking the 12th anniversary of the 9/11 attacks on the World Trade Center in New York.

Three police officers walk through the "Empty Sky" memorial to New Jersey's victims of the Sept. 11, 2001 terrorist attacks on Sept. 11, 2013, in Jersey City, N.J.

Navy Quartermaster Matthew Konchan of Johnstown, Pa., stands in a field of Black-eyed Susans as he waits to participate in a wreath laying with Secretary of the Interior Sally Jewell during a memorial service at the Flight 93 National Memorial, Sept. 11, 2013 in Shanksville, Pa.

Ann Ellis of New York sells flags and pins to passing pedestrians in New York, Sept. 11, 2013 as the twelfth anniversary ceremonies of the attacks of Sept. 11, 2001 take place at the nearby 9/11 Memorial.

A woman wipes her eyes after reading the name of her brother, Bobby Hughes, as friends and relatives of the victims of the 9/11 terrorist attacks gather at the National September 11 Memorial at the World Trade Center site.

Friends and relatives of the victims of the 9/11 terrorist attacks gather at the National September 11 Memorial at the World Trade Center site.

The names of victims are read aloud as friends and relatives of the victims of the 9/11 terrorist attacks gather at the National September 11 Memorial at the World Trade Center site.

The sun rises in back of One World Trade Center in lower Manhattan, seen from Jersey City, N.J., Sept. 11, 2013.

Carrie Bergonia of Pennsylvania looks over the name of her fiance, firefighter Joseph Ogren, at the 9/11 Memorial during ceremonies for the twelfth anniversary of the terrorist attacks on lower Manhattan at the World Trade Center site.

Mayor Michael Bloomberg stands near mayoral candidate Bill de Blasio (R) during the 9/11 Memorial ceremonies marking the 12th anniversary of the 9/11 attacks on the World Trade Center in New York City.

U.S. soldiers salute at a memorial to the 343 firefighters who died during the 9/11 attacks in New York City.

Lisa Deats looks up during a ceremony marking the 12th anniversary of the Sept. 11 terrorist attacks at the Betsy Ross House in Philadelphia.

The American flag is reflected in a 9/11 Memorial in Panama City, Fla., Sept. 11, 2013.

A firefighter stands near the entrance to the 9/11 Memorial during the 12th anniversary of the terror attacks, Sept. 11, 2013.

Members of the Philadelphia Police and Fire Pipes and Drums listen to remarks during a ceremony marking the 12th anniversary of the Sept. 11 terrorist attacks at the Betsy Ross House in Philadelphia.