​Vietnam orphans search for their roots

Forty years ago this month a military C5-A transport left Saigon with orphans headed for new lives in America. But a cargo door blew out, and the plane crashed. It killed 138, including 78 children.

By the time South Vietnam fell, many more Vietnamese children had left their homeland. And now, Barry Petersen tells us, some of those children, long since grown up, are coming home:

Tobi Snyder's certificate of naturalization. CBS News

At the memorial service, they came to remember that terrible day in that terrible war -- the crash that killed 138 people, 78 of whom were children.

But more orphans were evacuated in the frantic last days. During the Vietnam War, some 3,000 orphans came to the U.S. Orphans like Tobi Snyder, who was barely six pounds when she came to America.

"I have a real love for life," she said. "And I don't know if that has anything to do with it, but I am a survivor. I am a fighter."

And Stacy Meredith, given up by her mother when she was two. "As a child, you just don't understand how a parent could ever let you go," she told Petersen.

Sister Mary Nelle Gage volunteered at the orphanages starting in 1973. "One of the first things that I remember seeing was one of the little children reaching out from the crib and grabbing a cockroach to play with it," she said. "And I was horrified. But this is the way it is. These are the cards that you're dealt."

The Vietnamese say hundreds of thousands of children were orphaned by the war. Of those who came to America, some had lost their parents. Or, they were children who had American fathers that Vietnamese families didn't want.

But most babies came with no story.

"We had children who were found in the market, [left] on a bus, and then the police brought them to us," said Sister Mary Nelle.

And all these decades later, the bond endures. "It wasn't just a moment in time. We're bound forever."

For 20 years now, Sister Mary Nelle has been guiding orphans back to Vietnam -- and to the orphanages where they were babies.

On this day in Loveland, Colorado, she's at a bon voyage party for Tobi -- now married with three sons, and soon on her way to Vietnam. "I've always been curious of my roots," Tobi said. "I look around and most of my friends, they know where they're born. And I've just never been able to really know that. And so this trip to Vietnam will be as close as I can get to that."

All she knows is that she was a two-pound infant when she arrived at the orphanage. A few pieces of paper and a photo contain all the information she has about her beginnings.

Petersen asked, "What emotions do you have when you look at this? This is you."

"Yeah, I think it's just amazing and astonishing that any of us survived. I guess quite a few of us passed on."

Stacy Meredith also survived, but was haunted by not knowing her birth mother, or why she was dropped off at an orphanage as a toddler.