Arlington, Va. ? Arlington National Cemetery is expanding by 60 acres to make room to receive another generation of honored dead. Yet at the nation’s most famous cemetery, no one can say how many rows of white headstones will be needed by midcentury.

Workers felt the grounds tremble Sept. 11, when a hijacked airliner smashed into the Pentagon just beyond the cemetery fence. Sixty-five of those killed have joined Arlington’s ranks.

Construction cranes rise above the Pentagon as a hearse parks near a gravesite at Arlington National Cemetery. The cemetery is expanding by 60 acres to make room to receive another generation of honored dead.

“We can’t look at what may happen, whether or not there will be a war or disaster,” said Supt. Jack Metzler, in charge of finding room for the dead of the future. “We just deal with it when it happens.”

Cemetery planners rely on demographics and topography to predict that the expansion will add 35 years to the life of Arlington cemetery, allowing it to accept fallen warriors until 2060.

There should be room enough for 350,000 more veterans, dignitaries and unforeseen heroes, an average of 6,000 per year.

As millions of World War II’s fighters age, burials are expected to increase over the next five or six years, covering large swaths of land before tapering off again.

Most World War II veterans will not end up at Arlington, even if they meet the strict eligibility requirements. But those who do would help fill the cemetery by 2025 if it stayed at last year’s size of 612 acres.

So Arlington has begun its first growth since the 1960s. Last month, the National Park Service turned over 12 acres of woodland behind the historic home of Confederate Gen. Robert E. Lee, which is at the heart of the cemetery.

Congress also has approved putting graves on almost 50 more adjacent acres, already owned by the military, by the end of the decade.

The biggest chunk will come when offices sitting on a hill next to the Pentagon, called the Navy Annex, are torn down. An Air Force memorial also is planned for that site.

Distinguished names

Already, 275,000 people rest at Arlington. They include presidents John F. Kennedy and William Howard Taft, Supreme Court justices, the crew of the Space Shuttle Challenger, polar explorer Richard Byrd, boxer Joe Louis, and veterans of every war the United States has fought.

One of the simple marble gravestones marks the body of CIA officer Johnny “Mike” Spann, who on Nov. 25 became the first American to die at enemy hands in Afghanistan.

Forty-nine victims of terrorism are buried together on a far edge of the cemetery, within sight of the Pentagon. Only the “Sept. 11, 2001” date of death distinguishes them from the gravestones of the World War II veterans that flank them.

Others were buried near family members or their ashes were placed in the columbarium. Placement of the 65th marker, for a Navy man among five people whose remains could not be identified, is scheduled for March 11.

Exclusive requirements

With space at a premium, burials are normally 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.

So do all presidents, as well as high government officials with past military service. Other veterans who served on active duty can have their ashes inurned in the columbarium.

Congress is considering legislation to allow other veterans to be buried at Arlington, but the Army, which oversees the cemetary, opposes changes that would use up space more quickly.

Veterans groups have long pushed for more land. Bob Manhan, an Army retiree now working for the Veterans of Foreign Wars, says he wants the cemetery to keep making room, whatever may come.

“Maybe 100 years from now if no one’s visiting my grave site, a new family can be buried above me,” said Manhan, 69. “I don’t know how, but I hope it can remain an active cemetery. I’ve buried so many friends there.”