By all accounts, Katie Meyer's life was moving in a positive direction.
Meyer, 22, of Newbury Park, California, was on the dean's list at Stanford University, majoring in international relations. She was captain of the school's women's soccer team — a star goalie who worked to support other female athletes.
She had friends who adored her. Teammates looked up to her.
Most of all, she had a close-knit, loving family. Her parents spoke with her via FaceTime earlier this week. The conversation, they said, was about spring break. Katie seemed to be excited about a possible trip to Cancun.
"We had no red flags, no red flags that anything was wrong, that she was upset," Katie's mother, Gina Meyer, told NBC News’ Stephanie Gosk on TODAY on Friday.
Within hours of the conversation, Katie Meyer died by suicide.
"We're struggling right now," Gina Meyer said. "We have so many questions that I don't know if we'll ever have answers for concerning her death."
If Katie Meyer's parents sensed no detectable signs of distress, how can other families and caregivers monitor their children for suicidal thoughts?
"Unfortunately, we can't predict who's going to go on to die by suicide," said Julie Cerel, a licensed psychologist and director of the Suicide Prevention & Exposure Lab at the University of Kentucky. "Suicide doesn't discriminate."
An online search of "suicide warning signs" yields results such as sleeping too little or too much, mood swings and withdrawing from social situations.
But anyone who has been in contact with a teenager or very young adult knows those signs can also be frustratingly typical of normal behavior. Their bodies and brains are growing at different speeds. Hormones consistently render their moods inconsistent.
"Brain development goes on until about age 25," said Dr. Samantha Meltzer-Brody, head of the University of North Carolina's department of psychiatry. This is especially true for the part of the brain responsible for planning and self-control.
This age group, Meltzer-Brody said, is "much more likely to act on impulse."
"The only reliable warning signs," Cerel said, "are previous suicide attempts or talking about wanting to die."
"Despite how outwardly successful someone seems to be, their brain is telling them, 'people would be better off without you,'" she said.
Such thoughts are not limited to any one particular group of young people. According to the organization, Suicide Awareness Voices of Education, or SAVE, suicide is the third leading cause of death for 15- to 24-year-olds in the U.S.
No one will ever truly know what was happening inside Katie Meyer's brain when she died. But experts say that parents can use her story as an opening to a dialogue with children and teenagers.
Cerel suggested these opening lines: "Hey, we saw the suicide of this really amazing young athlete. What would you do if you were ever feeling this way?"
Emily Mudd, a pediatric psychologist at Cleveland Clinic Children’s Hospital, said the key is to make clear that physical and mental health are equal.
"If you have a broken bone, you’re going to see the doctor. If you have depression, you’re going to see a doctor," she said. What's important is to "create an environment in your home where your child feels like it's safe to disclose things," Mudd said.
Start normalizing conversations about mental health early, rather than waiting for signs of despair that may never come, experts said.
Cerel and colleagues at the University of Kentucky have begun work on a pilot program with school nurses across the state that aims to get young people to start thinking about the answer to that question, long before any suicidal thoughts may begin.
The program, called Code Red, is much like a fire escape plan. Just as adults teach children how to get out of the house in case of a fire, they must also help them figure out how to work through thoughts of ending their lives in case they ever occur.
The plan includes writing down specific "escape routes," such as which people the child could contact if they were ever feeling like ending their lives, or how they might relax and distract themselves until they could get help.
Katie Meyer's father, Steven, urged parents to talk to their children — no matter their age — openly about their mental health.
"You may have somebody who has been loved to the ends of the earth and back from the day she was born," he said. "You can love them fully, but you may not understand them fully."
If you or someone you know is in crisis, call the National Suicide Prevention Lifeline at 800-273-8255, text HOME to 741741 or visit SpeakingOfSuicide.com/resources for additional resources.