By Mark Guarino

New Orleans (Reuters) - Robert Templet was walking to breakfast on that Sunday, December 7, when he heard a plane motor surging at his back. He turned and saw the pilot, his goggles atop his head, smiling down at him before a torpedo fell from the plane's belly.

"It happened so fast, we didn't know what was going on," Templet told Reuters.

Stories like Templet's are being documented in "Infamy: December 1941," an exhibit opening on Wednesday, the 70th anniversary of the Japanese attack on Pearl Harbor, at the National World War II Museum in New Orleans.

Even though 70 years have passed since the attack killed nearly 2,400 American service men and women, the memories are still very much alive for veterans of that day like Templet, 91, of Metarie, a New Orleans suburb.

The exhibit is designed to tell the story of the attacks through personal items of its survivors. A wristwatch -- stopped at 8:04 a.m. -- of a sailor who plunged into the water from the burning USS Oklahoma. Letters home from prisoners of war arrested in Wake Island ("In the evenings I play ball. I am getting three meals a day. I was not wounded," one reads).

Dog tags, uniforms, a casket flag and other artifacts give the viewer a sense of those who suffered that day. Touchscreen kiosks allow museum visitors to access oral histories of veterans such as Templet recounting their firsthand experiences.

"You should be leaving this in a somber mood," said Eric Rivet, a co-curator of the exhibit. "This was not a good thing."

A salute to Pearl Harbor veterans at the museum on Wednesday will launch a two-and-a-half-day international conference featuring military historians in public seminars expected to dissect the raid on Pearl Harbor in Oahu, Hawaii, as well as Wake Island, Guam and the Philippines.

Besides the December 7 attack off Hawaii, Japanese also attacked and subsequently captured the Pacific islands that same week, with fighting lasting for weeks.

This year likely marks the last major anniversary of Pearl Harbor that will feature a significant number of living veterans to lend their stories in person. According to the New Orleans-based Pearl Harbor Survivors Association, about 2,700 member veterans remain from the 60,000 military personnel serving in the Pacific that day.

Emily Rosenberg, who teaches history at the University of California at Irvine, said it is "inevitable" that the attack's anniversary will "fade in its significance to American life" as more veterans pass away, much like what happened to Civil War commemoration when the last living soldiers of that conflict died early last century.

"We like to think that as a society we remember every single thing, but that's not the way things really work," said Rosenberg, author of "A Date Which Will Live: Pearl Harbor in American Memory."

The dwindling of Pearl Harbor veterans is especially troubling to Templet, a former Navy radio operator who says he is one of only a few survivors of the attack left in the New Orleans area.

He worries that young people "don't know what Pearl Harbor was all about."

Seventy years later, images of men jumping overboard from the warships into flaming ocean water burning with oil are etched in his dreams.

"I'll think I'm trying to help sailors in the water, it gets all confused. Then I'll wake up," he said. "It comes in moments."

Evans Brasset, 91, worked kitchen duty on board the USS Rigel the day he heard the planes.

"We thought it was a dummy run over the airbase," said Brasset, who lives in Harvey, Louisiana. "We didn't know until they started shooting. They were laughing at us."

At the end of the attack, Brasset's ship was torn open by more than 150 holes, caused by shrapnel above the water line. Despite the damage, it managed to save over 100 men from the USS West Virginia, which was set ablaze.

"You can't forget about something like that," Brasset said. "It doesn't just come off your mind."

"Infamy: December 1941" runs through February 19.

(Editing by Corrie MacLaggan and Greg McCune)