This is part of an occasional series called " Rewind: Where are they now? " It catches up with people who stumbled into the headlines -- and then faded from view.

Chowchilla, California (CNN) How long does it take to overcome the trauma of being kidnapped and buried alive?

For Lynda Carrejo Labendeira and her classmates, four decades haven't been enough.

As a fourth-grader, she and 25 other children were snatched from their school bus by three men, taken to a remote quarry and forced into a moving van buried six feet underground.

It was the largest mass kidnapping in U.S. history.

For 16 hours, the children waited for either rescue or death.

The younger ones cried helplessly. The older ones tried to comfort them. All of them buried in a "coffin," the stench of vomit and filth intensified by the searing California heat.

Now, 39 years later, survivors of the Chowchilla bus kidnapping say they're reliving that nightmare.

Fred Woods -- the last kidnapper remaining in prison -- could be freed by a parole board, despite having been sentenced to life without the possibility of parole.

"I just get nauseous at the very thought of it," Carrejo Labendeira said.

Now 49, she said she is "living the whole ordeal all over again ... the whole kidnapping, just the buried alive, just the flashes of everything that has happened."

From water balloons to guns

July 15, 1976, was a gorgeous day. It was the second-to-last day of summer school for the kids at Dairyland Elementary School in Chowchilla.

"We loved summer school. It was such a good time," Carrejo Labendeira said. "We did arts and crafts, woodwork, ceramics. I just remember doing water balloon tosses, and we'd play fun games like truth and dare out in the park."

It was so much fun that Carrejo Labendeira's "little boyfriend" at the time, Jeff Brown, started a petition that day asking for two more weeks of summer school. Everyone signed it -- the teachers, the students, even bus driver Edward Ray.

The school bus is now housed at Bright's Museum in Le Grand, California.

So the children -- ages 5 to 14 -- boarded the bus home, delighted. The youngest ones were still in their bathing suits after swimming in the community pool.

As they drove down the narrow Avenue 21, a van in the middle of the rural road blocked the bus.

"Its hood was up, and Edward, our driver, couldn't do anything but slow down and try to go around it," Carrejo Labendeira said.

"But being the gentleman farmer that he was, he started to offer help. And as quick as his words were coming out, they jumped on the bus with their guns pointed at us. And the rifle. And told Edward to go to the back of the bus."

No one could see the gunmen's faces. They had pantyhose pulled over their heads.

Carrejo Labendeira ducked under her fourth-row seat, just inches away from the barrels of the guns. Her three sisters who were also on the bus panicked in the back.

The gunmen drove the bus through a thicket of bamboo. The drive jostled the students with each stalk the bus hit.

"The bamboo was as high as the bus, and we were just being shaken all over," Carrejo Labendeira said.

The turbulence didn't stop until they reached a concealed ditch. That's where two vans were waiting. The gunmen told the children to get inside.

'No one could see in'

For the next 11 hours, Carrejo Labendeira said, "they drove and they drove and they drove -- it seemed endless."

None of the students knew where they were going.

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"It was dark, the windows were painted in. No one could see in, and no one could see out," she said.

Jennifer Brown Hyde, who was 9 at the time, said the conditions were miserable.

"It was hot. It was over 100 degrees," said Brown Hyde, now 48. "No water. No bathroom."

Eventually, after nightfall, they stopped at a rock and gravel quarry near Livermore -- about 100 miles northwest of Chowchilla.

Carrejo Labendeira suspects she knows why the kidnappers drove around so long.

"I'm sure they had to (wait) until a time when they knew no one would be able to be around, no workers, to see 26 children get buried."

'A giant coffin for all of us'

The California Rock & Gravel Quarry was owned by the father of one of the kidnappers, Fred Woods.

But at that hour, no one was around -- just the gunmen and their hostages.

The kidnappers asked each child his or her name, age, address and phone number. They also took a piece of clothing or a belonging from each student.

But the gunmen never explained why they were abducting the children.

"I only recall them ever telling us to shut up and be quiet," Carrejo Labendeira said.

With only some construction lights illuminating the dark quarry, the kidnappers ordered the children and bus driver into what looked like a massive grave -- a moving van hidden underground.

"It was buried into the earth. It was like a tomb," Carrejo Labendeira said. "It was like a coffin. It was like a giant coffin for all of us."

Kidnappers trapped 27 people in a buried moving van, the inside covered with wire.

One by one, the children climbed down a ladder and into the van, which was covered under several feet of dirt. After the last student entered, the kidnappers removed the ladder.

16 hours of hell

The children's underground prison cell was crudely stocked with a few supplies: cereal, peanut butter, bread and water. But there was only enough food to last one meal.

"There were times we all thought we were dying." Lynda Carrejo Labendeira

Right next to the food was the makeshift toilet -- a hole carved into a box.

Several mattresses lay scattered on the floor -- perhaps an indication of how long they would be held hostage.

Brown Hyde said she thought she was about to die, especially because the ventilation system had failed.

"The fans that they put in ... the batteries had died," she said. "In my small mind, you think, 'That's it.'"

Over the course of 16 hours, the "giant coffin" became a stench-filled hell. Children vomited amid the odors of urine and filth. The younger ones screamed and cried for their parents. The food quickly vanished.

"There were times we all thought we were dying," Carrejo Labendeira said.

"I promised God if I survived this, I would be the best little girl ... I'd be the best little girl my whole entire life."

A daring escape

As hope dwindled, the bus driver and some students devised a plan to get out: stacking the mattresses to escape through a metal plate in the roof.

Workers excavate the buried moving van where 27 hostages were trapped.

"If we're going to die, we're going to die doing something," Brown Hyde recalled. "We're not going to die sitting here."

But the plate was covered with a massive truck battery and several feet of dirt. The bus driver and several of the older boys struggled to move it.

"Edward's digging up and out, Mike's digging, Jeff's digging, Robert's digging," Carrejo Labendeira said.

She hid the entire time because she didn't know where the kidnappers were.

"Are they up there waiting for us? And are we going to get shot for coming out? Because all you saw with them were the guns."

But the bus driver and the others cleared an escape path, and the children -- some climbing up on each other's shoulders -- managed to flee.

Their timing was impeccable -- the kidnappers were asleep.

Dirty and exhausted, they stumbled to find help. And just above the quarry was a small building.

"There was a man up above, one man, and he knew exactly who we were before we even said anything," Carrejo Labendeira said.

"The gentleman came down and said, 'This world's been looking for you.' He knew exactly who we were."

Victims of the Chowchilla mass kidnapping managed to escape on their own.

Ransom plan gone awry

Despite coming from well-to-do families, the three kidnappers were seeking a $5 million ransom.

"I have no idea ... why they needed or wanted the money," their attorney Scott D. Handleman said. "They were greedy. That's evident. There's no justifying this crime, obviously."

Handleman said he believes the men were trying to get the money from the state's education department because of reports the state had a surplus at the time.

But the trio's ransom call didn't even go through. Phone lines to the Chowchilla Police Department were jammed with calls from the children's families and the media.

From life sentences to freedom

Woods, along with brothers Richard and James Schoenfeld, pleaded guilty to kidnapping and were each given 27 life sentences without the possibility of parole.

Fred Woods, Richard Schoenfeld and James Schoenfeld

That brought some comfort to Carrejo Labendeira's childhood.

"We felt safe in Chowchilla. We felt safe growing up knowing we were assured that they would never get out," she said. "Knowing that the kidnappers were in prison, we weren't scared they were going to come get us. They said, 'They'll never get out, you'll never have to worry.'"

Now, she says, she has to.

All three kidnappers became eligible for parole after an appeals court overturned their original sentences. The appellate court ruled the men caused no serious bodily injury; therefore they should have the chance for parole.

Richard Schoenfeld was paroled in 2012; his brother James was released earlier this year.

Handleman, their attorney, said the Schoenfeld brothers are not speaking to the media.

But he said Woods should also be paroled because he is not a danger to society. And he said the victims don't need to fear Woods if he is released.

"Mr. Woods has no animosity toward any of them," Handleman said. "He is absolutely apologetic and recognizes he committed a horrible crime."

But at a parole hearing Thursday, the board refused to release Woods. His next chance at parole likely won't happen for another three years.

Victims of the school bus kidnapping signed the bus after driver Edward Ray's death in 2012. Ray was hailed as a hero for helping the 26 children escape.

A lifetime of trauma

The young children are now in their late 40s and early 50s. Many suffer from claustrophobia and say the kidnapping has affected even their own children.

Lynda Carrejo Labendeira said she still grapples with flashbacks and panic attacks.

"It's not normal for someone who's almost 50 years old to be afraid of the dark," Brown Hyde said.

Until recently, she had to sleep with a nightlight on. And she still has chronic nightmares.

"The types of nightmares I have, I was prepared to die," she said. "I actually had nightmares where somebody killed me ... I saw myself at my own funeral."

Darla Neal, who was 10 at the time, said her "extreme anxiety" makes it impossible to live normally.

"I'm overwhelmed to the point that I had to leave work," she said. "I tell myself I should be able to shake this off and deal with it. Yet here I am -- a mess."

Brown Hyde said her children have suffered from her own kidnapping.

"If you have a very overprotective parent, which would be myself, your children don't get to lead a normal life -- get on a bus, go on a field trip, stay the night with a friend. And that's been very difficult," she said.

"It's been a life of hard work, trying to be normal."

When her oldest son started kindergarten, Brown Hyde left work every day for a week to follow the school bus and make sure her son arrived safely at his babysitter's house.

She knows that a child's life can change forever during something as simple as a bus ride home.