Hers is the parenting book everyone should read.

Sue Klebold and her youngest son. (Photo courtesy of Sue Klebold)

I have plans to speak to Sue Klebold, and I'm nervous. What do you say to a fellow mother whose distinctive last name—and youngest child—is synonymous with the Columbine tragedy? And what could she possibly have to teach other parents?

As it turns out, a lot.

Like many, I remember watching, horrified, as the events of Columbine unfolded on TV in April, 1999. And I remember afterwards thinking what so many others wondered about the two shooters, students Eric Harris and Dylan Klebold, who killed 13 people and wounded 24 others before taking their own lives: "Where were their parents?"

However, perhaps no one has had more reason to think about why Columbine happened—and how it might have been prevented—than Sue Klebold. Now, she has poured her reflections into a new book, A Mother's Reckoning: Living in the Aftermath of Tragedy, which has challenged, and shaken, many of my assumptions about parenting. It's a must-read for parents with teens or almost-adolescents. "I think I always knew I wanted to write a book," Sue Klebold tells me by phone. "I just didn't know that I would ever publish a book, to put my face out there and let people know who I was. I was very much afraid to do that." Klebold, who is donating all author profits to research and charitable foundations that focus on mental-health issues, doesn't harbor judgment against those who don't want to speak out. "I chose to become a public person because of who I am—I'm an extrovert, I'm a teacher, I like to write. But you have to understand that for survivors of tragedies such as this, that's an unusual response to have." (She has been in touch with the Harrises over the years, she says, and they were aware her book was being published this month. After grieving in very different ways, Sue and her husband Tom parted a few years ago.)

I tell Sue that I found her book to be such compelling reading, I'd stepped onto the wrong train that morning. She laughs gently and apologizes for my being late to work. My subway snafu is not her fault of course, but apologizing is what Sue Klebold does, and has been doing, in the 17 years since Columbine. With Dylan gone, she, Tom, and their older son (along with the Harrises) bore the anger, the blame, and the lawsuits (36 of them) for Columbine.

After Columbine, Sue and Tom were vilified. But perhaps no one was harder on Sue Klebold than Sue herself. And for years, she had had the same unanswered question for her son that everyone had:

How could you? How could you do this?

In the book, Klebold tells us who Dylan really was, before Columbine. In spite of media caricatures of a lonely outcast with no friends, Dylan was not that. He was on the shy side, but he had a small, close circle of friends (not just Eric), and the family's home phone rang through his high school years "to the point of distraction," his mother writes, with invitations to go bowling or to the movies. Dylan seemingly had much to look forward to. He was about to graduate. The week prior to the shootings, he'd picked out his dorm room on a road trip with his dad to the University of Arizona, where Dylan would study computer science.

Sue and Tom Klebold were what anyone would call involved parents: Tom was a work-from-home father who shared a snack and the sports pages with Dylan when he got home from school, played chess with him, and enjoyed projects with his "buddy," like rebuilding speakers and fixing up cars, including the 16-year-old BMW he'd bought Dylan for $400. An exceptionally bright child, Dylan began school a year early, and spent several grades in the gifted program. Dylan's mom, meanwhile, had a job in the community-college system helping disabled students. She did all the things good moms do: She took Dylan and his older brother to the neighborhood pool, monitored their intake of sugary cereals, organized Easter egg hunts, held movie nights in their family home, and strictly enforced a no-guns policy in their house, in spite of the fact that hunting and going to the shooting range are local pastimes in Colorado. Later, even the Klebolds' strong anti-gun stance would be criticized, and suggested as a "reason" Dylan became secretly fascinated with guns. (One need look no further than Sandy Hook and its shooter, who got his guns from his mother, to know how faulty that line of thinking is.) Until Dylan's junior year of high school, when he and Eric got arrested for breaking into a van and stealing electronics, it was Sue's older son she typically worried about. She fretted that year, but teenage boys do dumb things, she was told, and the two graduated from a junvenile diversion program early. Things calmed down, and by Dylan's senior year, Sue Klebold, who'd recently happily celebrated a milestone birthday, believed that her family was in a good place: her older son settled in a new apartment, her younger son ready to soon go off to college.

The image of the Dylan on TV, with gun in hand, so poorly reconciled with the child she had raised that for months, Sue Klebold clung to the belief that he must have been an unwitting or coerced participant, or acted in a moment of madness, or been on drugs. (She hoped he'd been on drugs—it would have been an explanation.) It wasn't until she and Tom watched videotapes made by Dylan and Eric, months later, that they had a new Dylan to grieve: a distant, angry Dylan who masterminded the eventual attack with Eric for months, whose plan for destruction—with bombs that failed to fully detonate—was much greater than the one executed that day.

Did Dylan have flaws that made him more vulnerable to participating in such a crime? Sue remembers how from a young age he hated to be wrong, to be embarrassed, to lose. He had a need for perfection and didn't like to ask for help, even when he needed it. Upon entering high school, an injury had kept Dylan, a passionate baseball fan, from making the high-school team, "a much greater loss than we knew," his mother writes, as the focus of his attention shifted from baseball to computers. His personal writings, discovered after his death, revealed a longtime, passionate and painful infatuation with a girl, although he'd never worked up the courage to speak to her. The sports-dominant culture at Columbine wasn't easy on Dylan or Eric, and they were targets of bullying (and then, bullied others themselves). In just one example, video footage showed football players elbowing Dylan in his side as they passed him in the hallway.

Fatefully, there was the troubling friendship between Eric and Dylan. When Dylan joined a soccer team in high school, his parents were proud. Upon losing a game, Eric lashed out openly at Dylan, blaming the loss on his performance. The Klebolds were in shock, but Dylan quietly walked away. "That's just Eric," he said. Dylan admits to his mother at one point that Eric is "crazy," and Sue suggests Dylan blame her when he didn't want to get together with Eric—only later did she realize that Dylan didn't do that with other friends, whom he had no problem saying no to. Now, Sue writes, she wishes she and Tom had been "brutal in our separation of the boys."

Still, none of these things, even all added together, are an adequate explanation for Columbine, Sue notes. And after all these years, she accepts none of us will ever have a clear answer.

But if there was one message that especially resonates in her book, and that could potentially help other parents, it's this: She wishes she had recognized Dylan's depression.

"I now believe that if Tom and I had been equipped then to recognize those signs, and been able to intervene as far as his depression was concerned, we would have at least have had a fighting chance to prevent what came next. Understanding Dylan's death as a suicide came almost as an afterthought to me. But for Dylan, the desire to die by suicide was where it all began." By the time Dylan had decided he was going to end his life, it didn't matter that he was spending a night at the prom or putting a deposit down on a dorm room right before Columbine—signs that led his parents to believe he was fine. But for Dylan, his suffering was mercifully about to come to an end.

Today, Klebold is a suicide- and violence-prevention activist. She makes no excuses for Dylan or for herself, and her deep compassion and sorrow for his victims ring true and sincere. (She asks me through her book publicist to please not post any pictures from Columbine, so as not to upset the families.) One of the student survivors, Anne Marie Hochhalter, paralyzed in the attack while she sat outside at lunch, recently wrote a Facebook post that went viral, in which she recalled with appreciation the personal, handwritten letter Sue and Tom sent her a few months after the shootings. "I have forgiven you," Hochhalter wrote.

As Klebold says to me in our interview, "The chances of your child becoming involved in a mass murder, like mine, are one in a million. One in millions, even. But the chances that your child is struggling with depression are strong. Everybody needs to be vigilant."

What signs does Klebold feel she missed? Dylan had friends, but he didn't feel as if he belonged. In personal writings he'd listed his "nice family" as one of the good things in his life, but saw himself as a burden. (She writes, "Tom and I did worry aloud about how we would pay for his college tuition, which haunts me to this day.")

One of the things that struck me while both speaking with Sue and reading her book: When our kids are small, for the most part, as their parents we handily solve their problems. The hardest things I had to do this week for my 4-year-old were to find her favorite stuffy to sleep with, administer drops for pinkeye, change her pajamas and clean her up after she got sick, and cuddle her on the couch. Every problem she had, I fixed it.

But as kids grow older, their problems become more complex. And more than ever, Sue Klebold warns from experience and from many conversations with leading mental-health experts, kids need their parents to stop being Mr. and Ms. Fix-Its, and to be really listened to. What's more, at adolescence they're entering the years where they'll encounter issues we parents painfully can't just smooth over: the humiliations of social rejection, or the pain of an unrequited crush. As a parent of two emerging adolescents, I find this idea, that I won't be able to fix everything for my children forever, one of the harder and more heartbreaking transitions to being a parent of older kids.

What can we do, as parents and for the children who live in our communities? We can be more vigilant about recognizing the signs of depression and other brain illnesses, says Klebold. Depressed adults may appear sad and low-energy, but teens (especially boys) tend to withdraw and show increased irritability, self-criticism, frustration, and anger. Unexplained pains, whininess, sleep disorders, and clinginess are common symptoms of depression among younger children, she writes. We talk candidly about so many health issues. Why not mental, or brain, health?

In spite of the anxiety, depression, and PTSD Sue Klebold suffered herself after Columbine, she came to learn she was not alone in her grief. She received 3,600 letters from around the country—the vast majority supportive and sympathetic. There were many letters from other parents, who didn't recognize the warning signs of depression and suicide in their own children.

Columbine would be so much easier to understand if Dylan Klebold came from a horrible home. The fact that he did not is probably why Klebold's story scares people. Sue Klebold did everything seemingly "right," and this still happened in her family. "When I speak to parents, they want to believe that Dylan came from a bad environment, or that we're bad parents," she tells me. "I'd say that people who believe that this couldn't happen to them, though, are less likely to recognize the neediness of their children—that maybe what they're seeing is not reality, and that this [depression and suicide] could happen to anyone."

"We have got to start having conversations about this, without trying to simplify the complex factors involved in suicide," adds Klebold. "And I thought the only way I could move this conversation forward is to open up and put it on the table."

Now, it's our turn to listen.

Gail O'Connor is a Senior Editor at Parents and a mom of three.