Updated

Filmmaker Rory Kennedy -- the youngest child of Bobby and Ethel Kennedy -- has made a film about Americans heroes of whom few are even aware with her documentary "Last Days in Vietnam," premiering this week at the Sundance Film Festival.

"I came across these pretty extraordinary stories of men and women on the ground who really went against U.S. policy, which at that point was just to evacuate only Americans," Kennedy told FOX411. "They risked their lives to save South Vietnamese. It was a story I didn't really know anything about, and I figured most other people didn't either. It's such an important chapter in our history, and yet very few people know what happened in those final days. For a topic that has been written about so much, this really is an original story."

"Last Days in Vietnam" probes the chaotic final weeks of the Vietnam War as the North Vietnamese Army closed in on Saigon and panicked South Vietnamese  desperately attempted to escape. On the ground, American soldiers and diplomats were forced to grapple with a moral dilemma: whether to obey White House orders to evacuate only U.S. citizens, or save as many Vietnamese lives as possible. Kennedy's film sheds light on the secret operations conducted by troops and officials as they sought to save their Vietnamese friends.

So why has it taken so long for this story to be told? Kennedy says many of the heroes, such as Army Captain Stuart Herrington, who worked under the Pentagon's radar to save more than 30,000 Vietnamese lives, simply never viewed their actions as heroic.

"When he came back to American soil, after this extraordinary act, he and his entire crew were spit on. They never saw it as heroic," she said.

Kennedy says others who went against orders to put Vietnamese locals on boats and helicopters don't think about the lives saved, but instead harbor guilt about the lives they couldn't save.

"Last Days of Vietnam" features a range of interviews with key political figures including former Secretary of State Henry Kissinger, Special Forces Advisor Richard Armitage, and White House Press Secretary Ronn Nessen. But even with her prominent last name, Kennedy said it took some convincing to get such high-ranking participation.

"There was some resistance," Kennedy admitted. "It took a little bit of encouraging of these folks but pretty much everyone who I wanted to be in the film agreed to be in the film."

Aside from acknowledging the courageous actions of many American troops and government officials in Saigon, the filmmaker also hopes audiences take away an extra appreciation for Vietnamese culture within the U.S.

"I hope this film starts a dialogue and opens up deeper conversation and appreciation for them," she said.

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