FORT WORTH, Texas — Linda Lorenz received a telephone call in late February from a friend, telling her that her son would indeed be on the Wall.

"I just broke down," she said.

In mid-May, Linda Lorenz will be flying to Washington, accompanied by a friend who can help her get around for the Vietnam Veterans Memorial ceremony.

She is 83 years old, and while she looks 10 years younger, she is increasingly frail.

For 40 years, the Lorenz family has been just her. Her husband died close to 50 years ago, and she never remarried. Together, they had only Hans.

So when she is gone, so too is her family.

"He was an only child. I was an only child. His father was an only child," she said. "Some families just end. That's it."

War courses through the Lorenz family.

Hans' father fought for the Germans in World War II, and his grandfather in World War I. Military service goes back four generations.

"The military was his ideal," she said of Hans. "I guess he inherited it."

Born Aug. 21, 1944, in Neuenburg, Germany, Hans and his mother immigrated to Ontario, Canada, in 1957.

"I thought I would get Hans away from all the troubles in Europe," she said.

He fit a German stereotype: 6 foot 3, square jaw, blond hair, blue eyes, athletic build. He loved ships and joined the Canadian Navy after high school, but he really wanted to be in the U.S. Marines.

His mother argued with him, pleaded with him, not to join. She saw the war brewing in Southeast Asia and had had enough of war in her family. But he wouldn't be talked out of it.

He enlisted in 1965.

"It was a paralyzing time for me," she said.

Hans landed in Vietnam on Jan. 31, 1966, a member of the 1st Battalion, 3rd Marines, based near Da Nang.

Just two and a half months later, at 7 p.m. on April 11, Hans was disposing of contaminated gasoline when it blew up. He was evacuated 45 minutes later, according to his unit's log book for that day.

At her house in Midland, Ontario, his mother knew something bad had happened. No one had to call her.

"A mother's intuition," she said. "That's nothing special with me. A million other mothers have it."

She received a telegram two days later at work. That night, she took a telephone call from Hans, who called from a field hospital.

"Mom, it's a small injury," he told her. "Don't worry about it. I'll be OK."

But Linda Lorenz knew he was lying. On April 15, she and Hans' girlfriend flew to Oakland, Calif., to meet him.

"He didn't speak much," she said. "Sometimes he spoke German. They did everything so he wouldn't feel pain."

The living room grew quiet. "I think that's enough of that."

Eleven days after Lorenz arrived in California from his base in Vietnam, bacterial infections ravaged his internal organs, shutting them down one by one. At 2 p.m., April 26, 1966, he died of cardiac arrest.

Flown in from the war zone in Vietnam, Lorenz was never considered a Vietnam War casualty by the Defense Department, and as a result did not appear on the Vietnam Veterans Memorial in Washington, D.C., when it was unveiled in 1982.

Over the years, his mother and her friends made entreaties to the Marine Corps for approval to have his name added. Each time, the Marine Corps denied her.

He was ineligible for the Wall because he died in an accident, and as she was told, the Wall is only for those killed in combat.

Only that's wrong. Dead wrong.

The Wall was never intended to exclude men and women who died of nonhostile injuries during the years of the war. Indeed, the Wall already bears the names of 10,500 people who died with no help from the enemy.

But because of what appears to be a misinterpretation of the Wall's criteria, dozens of eligible names may have been wrongly denied permanency on the Wall, according to the expert who discovered the problem. It also means that the services are not always consistent in their decisions, meaning that what will get a soldier on the Wall won't get a Marine on it.

What appears to be happening is that employees in some of the services' casualty offices are confused about the criteria for deaths during and after the war, and no one in the Defense Department is reviewing the rejection letters to ensure the right decision was made.

The result is letters like the one Linda Lorenz received in 2004 from A. Hammers, head of the Marines' casualty section in Quantico, Va.:

"The consensus was that the criteria should not be expanded beyond the original, i.e., to recognize those service members who died as a result of combat with enemy forces. ... His death was not attributable to combat wounds, therefore he is ineligible to have his name added to the Vietnam Veterans Memorial."

After nearly 20 years, though, Lorenz's mother finally got the letter she wanted.

Alerted by a dogged Vietnam researcher in Maryland and his congressman, the Defense Department intervened in her son's case and gave its approval in February for Lorenz's name to go up on the Wall.

Maj. Michael Shavers, a spokesman in the Defense Department, called the Lorenz case an "oversight."

"After coordinated review with the Marine Corps ... this case was determined to be an omission," he wrote in an e-mail.

The name of Hans J.R. Lorenz will be engraved in time for Memorial Day service in Washington.

"That was the last thing I could do for him," Linda Lorenz said from her apartment in west Fort Worth. "Now it's done."