Remembering the terrorist attacks of Sept. 11, 2001

Carrie Bergonia of Pennsylvania looks at the name of her late fiance, New York firefighter Joseph Ogren, at the Sept. 11 Memorial at the former World Trade Center in New York. Ogren was killed in the terrorist attacks.   (Chris Pedota / Associated Press)

Jon Gillette and Annie Block-Weiss stand among flags at Pepperdine University in Malibu.  (Gary Friedman / Los Angeles Times)

Los Angeles firefighters attend a ceremony at the Fallen Firefighters Memorial in Hollywood.   (Al Seib / Los Angeles Times)

The Empty Sky Memorial in Jersey City, N.J., which honors the state’s victims of the terrorist attacks.   (Mel Evans / Associated Press)

President Obama during a moment of silence at the Pentagon.  (Pablo Martinez Monsivais / Associated Press)

Los Angeles firefighters from Station 27 stand near the American flag bearing the names of New York firefighters killed in the attacks.   (Al Seib / Los Angeles Times)

Friends and family members gather at the 9/11 Memorial in New York.  (Alejandra Villa / Associated Press)

A man sits in the Pentagon Memorial park as he waits for President Obama to speak at a ceremony at the Pentagon 9/11 Memorial to commemorate the anniversary of the September 11, 2011 attacks, in Washington, D.C.  (Pete Marovich / EPA)

A visitor kisses a name on the wall containing the 40 names of the crew and passengers of Flight 93 at the Flight 93 National Memorial during a candlelight remembrance on Tuesday in Shanksville, Pa.  (Gene J. Puskar / Associated Press)

The twin towers of the World Trade Center burn behind the Empire State Building in New York.   (Marty Lederhandler / Associated Press)

United Airlines Flight 175, with 65 people aboard, is about to crash into the World Trade Center south tower.   (Carmen Taylor / Associated Press)

The first World Trade Center tower implodes.   (Greg Semendinger / AP Photo/NYPD via ABC News)

The collapse of the towers covered people covered in dust.  (Gulnara Samoilova / Associated Press)

Dust and debris covers dishes and silverware in an apartment in the Battery Park area of lower Manhattan.  (Quyen Tran / Associated Press)

The lower Manhattan skyline remains shrouded in smoke four days after the Sept. 11 terrorist attack on the World Trade Center.  (Dan Loh / Associated Press)

From left, New York City Mayor Rudolph Giuliani, New York Gov. George Pataki, President Bush, Sen. Charles E. Schumer and Fire Commissioner Thomas Van Essen inspect the damage three days after the attack.  (Doug Mills / Associated Press)

Firefighters carry flag-draped remains from the debris field where the north tower of the World Trade Center once stood.  (Louis Lanzano / Associated Press)

Robert McCann, 4, stands with his father, Robert, and firefighters during a funeral for Capt. Timothy Stackpole in Brooklyn.  (Wally Skalij / Los Angeles Times)

Rescue workers are lowered into the ruins of the World Trade Center.   (Robert Gauthier / Los Angeles Times)

A military helicopter takes off from a field near the damaged portion of the Pentagon following the attack.  (Al Schaben / Los Angeles Times)

Firefighters hold on to their hats at the site of the World Trade Center as a strong wind whips through during a first anniversary commemoration.  (Eric Gay / Associated Press)

Benjamin Shinsky, 6, of Cleveland looks at a display of little wooden angels with the names of passengers on them at a temporary memorial near the Sept. 11 crash site of United Airlines Flight 93 just outside of Shanksville, Pa.  (Keith Srakocic / Associated Press)

A firefighter salutes during a commemoration ceremony at Zuccotti Park, adjacent to ground zero, on the ninth anniversary of the terrorist attack on the World Trade Center.  (Jason DeCrow / Associated Press)

Visitors to the World Financial Center take in the view of the construction site at ground zero.  (Mary Altaffer / Associated Press)

President Barack Obama visits ground zero to honor the men and women who lost their lives on Sept. 11, 2001.  (Carolyn Cole / Los Angeles Times)

A woman mourns the loss of her son, 10 years after the attack.   (Carolyn Cole / Los Angeles Times)

Family and friends of those who died on Sept. 11 visit the memorial during the 10th anniversary ceremonies at the site of the World Trade Center. Stephen Simone came wrapped in an American flag.   (Carolyn Cole / Los Angeles Times)

Lights symbolizing where the World Trade Center once stood shine on a cloudy night during 10th anniversary ceremonies.  (Carolyn Cole / Los Angeles Times)