Josephine Duff McIntosh Olsson searched intently for a man's name on the Lisbon Maru survivors' memorial wall at Zhoushan Marine Cultural and Art Center in Zhoushan, Zhejiang province — a man she had never met in person.

When she finally found it, she pointed to the name for those around her, tears streaming down her face.

"That's my great-uncle, Joseph Duff!"

In October 1942, Joseph Duff was among the 1,816 British prisoners of war being transported from Hong Kong to Japan aboard the Japanese cargo ship Lisbon Maru.

The vessel was not marked as carrying POWs, and it was torpedoed by a US submarine off the coast of Zhejiang province.

Japanese guards sealed the prisoners below deck, and those who managed to escape were met with gunfire. In all, 828 men died.

In the midst of the chaos, local fishermen from Dongji Island in Zhoushan risked everything to launch their small boats and rescue 384 survivors under Japanese gunfire.

On the island, they gave the starving prisoners their own meager supplies of fresh water and food.

Later, when Japanese troops landed to search for escapees, the fishermen hid three British POWs in a seaside cave, secretly bringing them food every day.

In time, they safely transferred the men all the way to Chongqing, where the survivors used a radio broadcast to reveal the truth about the sinking of the Lisbon Maru to the world.