Editor's Note: An archive forgotten for decades helps bring some justice for Italian victims of Nazi atrocities. In San Pancrazio, locals remember massacre victims with an annual candlelight vigil. Watch CNN International's World's Untold Stories Saturday and Sunday.

San Pancrazio, Italy (CNN) -- The din of approaching vehicles shattered the silence over San Pancrazio at daybreak. It was June 29, 1944, when retreating German SS troops stormed the remote Tuscan village nestled in the Italian countryside.

Caught unaware, terrified villagers were forced from their homes and brought to the main square. After the women and children were escorted from the village, the men were taken to a cellar and executed. In all, 73 were killed.

That tragic day would forever haunt survivors, whose fathers, husbands and sons met a horrific end. The long and painful journey to justice would take decades.

San Pancrazio, about 50 kilometers (31 miles) south of Florence, is one of hundreds of places across Italy where unspeakable atrocities targeting civilians occurred during World War II.

Between September 1943 and April 1945, the Nazis' calculated campaign of violence spared no one. In some cases, women, children and the elderly were viciously murdered alongside the men, as villages were overrun.

"15,000 Italians were killed," said Dr. Gianluca Fulvetti, a historian who has published two books on wartime atrocities in Italy. "This wasn't only a war fought between armies. It was a war on civilians who unwittingly got involved and paid with their lives."

Tuscany was one of the hardest-hit regions, as German troops retreated north following the liberation of Rome. Fulvetti estimates 3,650 people died there, the majority in June 1944.

The war on civilians was triggered by Benito Mussolini's downfall in July 1943 when the Fascist dictator was arrested, paving the way for Italy's armistice with the Allies.

Tens of thousands of Italian soldiers who had fought under Mussolini then took up arms to fight Nazi Germany.

In March 1944, partisans in Rome attacked a column of SS police officers, killing 33 Germans. On orders from German high command, 335 men and boys were rounded up and executed at the Ardeatine Caves, near Rome. The reprisal killings set the stage for how Germany would conduct the remainder of the war in Italy.

"Troops were ordered to retaliate against civilians as punishment for partisan actions," Fulvetti said. Any form of resistance by civilians was cause for punishment, even simply refusing to shelter or feed German troops.

Clashes between local resistance and German troops near San Pancrazio spread fear of reprisals throughout the countryside. They came on June 29, when units of the notorious Hermann Goering Division stormed into homes and rounded up villagers in the town square.

Goffredo Cinelli, who had served in Italy's air force before Mussolini's ouster, hid in the attic, as his father was led away. "I heard the women and children crying," he said. "My mother later said she went to speak to my father. A soldier turned her back and told her they were taking him to be tortured. She and my father both cried."

The men's actual fate soon became clear. Inside the cellar of a farmhouse, the local priest pleaded for his parishioners' lives. After saying Mass, he was the first to die by gunfire at close range. The others were similarly executed. The Germans later set fire to the corpses, and to villagers' homes.

That same day, 173 people were killed in the nearby villages of Cornia and Civitella.

Gabriella Panzieri lost several family members in the San Pancrazio massacre. Six years old at the time, she describes taking refuge in the woods with her mother. "I remember the flames rising from our village that night. It was like the whole world was on fire," she said.

Allied troops reached San Pancrazio, by then reduced to rubble, two weeks later.

After the war, in 1946, a military court sentenced a former SS commander to life in prison for the Ardeatine Caves massacre. But plans for further trials were soon shelved.

The approaching Cold War dampened enthusiasm for ferreting out Nazi war criminals. "There was a growing reluctance to embarrass Germany," said Dr. Paolo Pezzino, who teaches contemporary history at the University of Pisa.

"International justice took a back seat to realpolitik. The Communists were now the enemy. It was no longer the case to look back at the past but to face the future."

Silence reigned for half a century. Then, in 1994, a startling discovery was made at the military tribunal in Rome. A forgotten archive revealed a treasure trove of evidence on hundreds of wartime atrocities, documented by Allied and Italian investigators.

Pezzino served as consultant to a parliamentary commission that looked into the motives behind the files' concealment. He maintains that if they had been properly forwarded to the military courts immediately after the war, more war crime trials could have resulted. "This was a cover-up in every sense of the word," he added.

The discovery of the so-called "cabinet of shame" triggered public outcry -- and a renewed call for justice.

"I felt I had a moral obligation to provide answers," said Marco De Paolis, currently Italy's chief military prosecutor, who played a key role in reopening war crime cases. "And to bring a sense of justice to hundreds of people who had been waiting over 50 years."

Since 2002, De Paolis has tried more than a dozen cases, several resulting in convictions.

By 2007, all but one defendant accused in the San Pancrazio massacre had died. Max Josef Milde, 82 when the trial started, was tried in absentia, convicted and sentenced to life in prison for the shooting deaths of 203 of the men, women and children in San Pancrazio, Civitella and Cornia.

"When the sentence was pronounced, I felt the cry of justice," recalled Mayor Sauro Testi, who accompanied survivors and family members to the sentencing. "The state had finally responded."

Milde has always maintained his innocence, and has not shown up to serve his sentence.

While German authorities helped with the case, Germany does not extradite its citizens convicted of war crimes in other countries.

Still, his conviction was welcomed by many victims' families.

"It was an historic moment in which someone was declared guilty," says Michele Panzieri, who lost several family members to the tragedy. "It's important to never forget, but you have to forgive in the end."

Cinelli, now 92, the air force veteran whose father was killed in the massacre, had a different reaction.

"I knew nothing would be resolved in the end. After 60 years?" he shrugged. "It was a time when there was enormous hate between those who were fascist and those who weren't. It was a tremendous struggle."

Even after the conviction, San Pancrazio refuses to forget its past. Every year, villagers hold a candlelight procession on the anniversary of the tragedy, to remember the victims.

Read "No hate at memorial"

Michele Panzieri's father, Enzo, is president of a local association dedicated to preserving the memory of the tragedy. He was an infant when the front swept through Tuscany and took with it the father he never knew.

On a recent afternoon, he could be seen talking to a group of students inside the farmhouse cellar -- now a museum -- answering their questions with restrained candor and insight. "I enjoy talking to the kids and sometimes I've seen them get emotional," Panzieri said.

"The youth of today will lead Italy tomorrow. They need to see these things so they're never repeated."