It's a short piece of torn, riveted metal, not worth a dollar at a scrap yard.

But to Dennis and Eileen Kirban, it's an honored relic, a physical token of the powerful emotional tie that binds their family to a long-ago day of horror and heroism.

It came, they say, from a Japanese warplane downed at Pearl Harbor during the surprise attack that plunged the United States into World War II. After the attack, which left nearly 3,600 Americans dead or wounded, Army Pvt. Nicholas Tinari Jr. picked up a chunk of aluminum from the wreckage of an aircraft that had tried to kill him and others who served that day.

Since then, the fragment has been passed within the family, traveling from the lush islands of aloha to the suburban lawns of Bucks County, unrecognizable and anonymous but for a faded, handwritten notation:

Dec. 7, '41, Pearl Harbor, Hawaii.

The metal is smooth in some places, jagged in others, no thicker than cardboard - for the Kirbans a symbol of their loved ones' luck and sacrifice and a reminder of the quirks of war.

"It encapsulates a lot of things," said Eileen Kirban, Tinari's daughter.

Coincidentally, both her father and grandfather were at Pearl Harbor on the day of the attack, one a soldier, the other a civilian. The two met the day before, and later became family when the younger man married the daughter of the elder.

Eileen Kirban's grandfather Phillip Carvalho was a native of Hawaii, the second of 18 children. In 1941, he worked painting the U.S. military ships docked at Pearl Harbor. On the morning of Dec. 7, he finished an overnight shift on a destroyer, then went to a nearby building to clean his brushes.

He was just leaving when Japanese planes appeared overhead.

Tinari, a native of Huntington Valley, was stationed at Schofield Barracks, an Army base adjacent to Wheeler Airfield, about 15 miles north of Pearl Harbor.

Tinari worked in the motor pool as a mechanic, repairing and servicing Army vehicles. He decided to get a tattoo, spending $70 for two images: a large head of Christ on his chest, and a small inking on his arm that bore the date: Dec. 6, 1941.

The next morning, Tinari went for coffee in the barracks kitchen. He was just setting his cup on a table when the ground shook and windows shattered.

Everyone ran outside - planes flashed overhead, seeming close enough to touch, Tinari recalled in a taped family interview.

Wheeler Army Airfield was a main target, as the Japanese tried to prevent an American air response by destroying planes on the ground. Schofield Barracks was strafed by gunfire that killed at least one man and wounded more than a dozen.

In two hours, the attack on Pearl Harbor killed 2,403 Americans and wounded 1,178, and sank, beached, or damaged 21 ships. Nearly half the dead were killed on the battleship Arizona, whose submerged hulk has become an iconic memorial, visited by more than a million people a year.

In the days after the bombing, military personnel and civilians on the island were pressed into recovery efforts, collecting debris that had been cars, trucks, buildings, and hangars. More than 300 American planes were damaged or destroyed. The Japanese lost 29.

Tinari made his way to a crashed Japanese plane and picked up a piece of A-shaped metal with a row of rivets on each leg, keeping it as a souvenir, he said on the audiotape.

The war against Japan and Germany would rage for nearly four years. Tinari remained stationed in Hawaii - and married Carvalho's daughter, Margaret.

Today, at 88, her abiding sense of Pearl Harbor is the emotion: the fear provoked by the scream of the aircraft engines that day, the horror of two girls across the street being shot to death from the air as they put on their shoes to go to church.

Tinari was discharged from the Army in 1945, and opened Nick's Body Shop in Hilo. Carvalho worked for him there, with Nicholas doing the body work and Phillip painting the cars.

In 1946, a tsunami destroyed parts of Hawaii and swept away the body shop. Nicholas and Margaret rebuilt, but their minds were shifting elsewhere.

Nicholas' father had died a year earlier, and the couple decided to move to Pennsylvania to help his mother. They departed in the winter of 1946-47 - Margaret bought a warm red coat for the trip - and left some belongings, including the warplane scrap, with her father.

In Lower Moreland, Tinari started a paving business. He and Margaret had seven children - and eventually grandchildren and great-grandchildren.

Decades after the war, in 1996, Carvalho traveled to visit the family in Pennsylvania. He gave the piece of metal to his daughter. She passed it to her son-in-law, Dennis Kirban, a Vietnam veteran.

"It's like a piece of the Titanic," said Dennis, who with his wife runs Kirban Performance Products in Plumsteadville, Bucks County.

The shard of the plane is kept in the Kirban home among other mementoes from family and friends who served in wartime. The metal remains unchanged even as the people around it grow older.

Tinari died in 2001, age 82. Carvalho died in 2007 at age 97.

The youngest survivors of Pearl Harbor are now in their 90s. Among all veterans of the war, fewer than 900,000 remain, and they're dying at a rate of 492 a day, according to the National WWII Museum in New Orleans. Not long from now, everyone who served then will be gone.

What's left, in the words of an author who wrote of another war, are the things they carried - the gear and equipment, the photos and memories, the unusual items now cherished by families.

Several times, Eileen Kirban traveled to Hawaii with her parents, listening to her father talk about what occurred there, and visiting places he knew, including Schofield Barracks.

The image of Christ on his chest faded a bit over the years. His recollection of Pearl Harbor did not.

"We really cherish old memories," said Eileen Kirban. "These kind of things are really important."

jgammage@phillynews.com215-854-4906@JeffGammage