"While there's nothing one of us can do to bring back those loved ones, we can celebrate who they were, how they lived their lives and remember how their lives were lost, in a struggle dedicated to the eternal truth of freedom and the human spirit," Defense Secretary Donald H. Rumsfeld said.
Rumsfeld spoke next to a flag-draped casket containing cremated remains from the Pentagon rubble that could not be identified. For five of the victims, the internment in Arlington will be the only burial because no remains were confirmed to be theirs.
The five include a 60-year-old retired Army colonel and a 3-year-old girl killed with her parents and sister aboard hijacked American Airlines Flight 77.
Relatives of the victims sat solemnly, some hugging and weeping, others wiping away tears, as the crowd sang "Amazing Grace" and listened to eulogies from military chaplains.
"Know that your country shares your sorrow, mourns your loss and prays that God will comfort you," Rumsfeld told the families.
A five-sided granite marker bearing the 184 names will stand over a shared grave at the Arlington National Cemetery — the nation's most prestigious burial ground — holding the unidentified remains.
The 4-foot-5-inch-tall marker, with names of the dead inscribed on aluminum plaques, will be placed over the grave later, said Jennifer Lafley, spokeswoman for the Army Military District of Washington. The Army oversees Arlington cemetery.
Most of the 64 victims already interred at Arlington are nearby under simple headstones, within sight of the repaired Pentagon.
In some cases, as recovery efforts continued, additional remains were identified after a person was buried. Some of their families chose to have those fragments held for the common burial site, Lafley said.
Many of the dead, including some who were working inside the Pentagon on Sept. 11, did not qualify for burial at the nation's most famous cemetery.
Arlington is generally reserved for active duty personnel, military retirees, retired reservists who reach age 60, winners of the military's highest decorations, and former prisoners of war. Their spouses also qualify.
Among the 275,000 people buried there are presidents John F. Kennedy and William Howard Taft, the crew of the Space Shuttle Challenger, and veterans of every war the United States has fought.
A year and a day after the Sept. 11 terrorist attacks, all of the dead from the Pentagon attack also share in the honors of Arlington.
"It's nice that they're remembering all the victims," said Steve Push, whose wife, Lisa Raines, died inside the Pentagon. She was buried in November; Push said he wouldn't attend the additional service.
Some 13,000 people gathered to grieve and hear President Bush's words at Pentagon memorial service on Wednesday, as Sept. 11 was remembered across the nation. The Defense Department also plans to build a larger monument at the Pentagon.
The five victims whose remains were not identified are:
Dana Falkenberg, 3, who loved dressing up as a princess and died alongside her sister Zoe, 8, and parents Leslie Whittington and Charles Falkenberg, as they began a trip to Australia.
Retired Army Col. Ronald Golinski, 60, an avid golfer who worked as a civilian employee at the Pentagon. A memorial headstone, used when no remains are present, was placed for him at Arlington in December.
Ronald Hemenway, 37, a Navy electronics technician first class who left behind a 3-year-old son and 1-year-old daughter. His memorial headstone was placed at Arlington in March.
James T. Lynch, 55, a civilian video technician for the Navy known for handing out butterscotch candies to everyone he passed.
Rhonda Rasmussen 44, a civilian worker for the Army and mother of four who was planning to transfer to California when she died.
Five sets of remains believed to be those of the hijackers, because they did not match DNA provided by victims' families, were turned over to the FBI in February and will be excluded from the burial, officials said.