Mark Gagnon

The same foreigners who tried to save lives in 1937 now help the world understand the full truth.

And in the end, seven Japanese leaders were executed for their role in these war crimes.

General Matsui Iwani and Foreign Minister Koki Hirota were specifically persecuted for their Nanjing massacre.

Many believed responsibility should have gone higher, but the tribunal could only do so much.

And it was technically justice, but it was never going to mend the damage that was left behind.

And today in Nanjing, there's a memorial hall built for the victims of this massacre, a huge, quiet complex visited by millions every year.

Chinese students come to learn, tourists walk through in silence, families of survivors stand before the exhibits and remember.

Inside are photographs that are honestly hard to look at, testimonies that are really difficult to hear, and artifacts pulled from these mass graves, from bones to clothing to personal items.

Researchers have spent decades trying to identify the victims, carving their names into stone so that they would never be forgotten.

It's part museum, part cemetery, and really it's just a place to make sure that the world can't forget this atrocity.

The survivors who lived into modern times became witnesses.

They spoke in schools and gave interviews and recorded their stories on camera.

Their children and grandchildren continued that work, fighting to keep Nanjing 1937 in the world's memory.

They know how easily denial creeps in and how quickly people forget what they didn't see.

The foreigners who stayed, specifically Rob, Vautrin, and Wilson, and many others, are honored in China as heroes.

Their names are engraved on monuments, their diaries are taught in classrooms, and they're remembered for one simple reason.

They didn't walk away.

They stayed when staying meant everything and easily could have cost them their lives.

But for many, their lives were not easy after Nanjing.

Minnie Votrin returned to the U.S.