By Stephanie Stahl

PHILADELPHIA (CBS) — Thousands of people are expected to turn out at the Philadelphia Museum of Art on Sunday for the annual Out of the Darkness Walk to raise awareness about suicide. Millions of families are touched by suicide and the numbers recently soared among teens and young adults.

For parents, there’s nothing worse.

“He was the happiest kid, always smiling and laughing,” Rebecca D’Ulisse said.

From the outside, Eric D’Ulisse looked like he had a great life and was about to graduate from West Chester University.

Then one night, the doorbell rang at his mom’s house in Blackwood, New Jersey.

“The chaplain told me my Eric was gone. I just fell apart,” she said.

D’Ulisse is among a growing number of parents who’ve lost children to suicide.

“We didn’t see it coming. That’s what’s scary,” she said. “I thought he looked to have it all, doing well in school, good grades, friends at school.”

She says Eric, who was 22, suffered with depression. She doesn’t know if he was taking his prescribed medication or not.

“This is Ally, his beloved Ally,” D’Ulisse said.

Taking comfort with her son’s cat, D’Ulisse says in addition to being depressed, Eric was bullied in middle school like so many other kids.

She thinks there’s another component adding to why so many young people feel sad and alone.

“There’s a disconnect, even when kids are together they’re on their phones,” she said. “They’re not engaging with each other. I think it’s a combination of the lack of connection, technology, bullying, being on 24/7.”

Eric left a note, apologizing and saying his parents had been great but that his self-esteem had been ruined by the bullying.

“At the end, he wrote he didn’t want to disappoint anymore,” D’Ulisse said. “That was his last line so it was obviously the depression coming through.”

D’Ulisse is on a mission to raise awareness about mental health issues that are often hidden, and she’ll be part of the upcoming Out of the Darkness Walk for the American Foundation for Suicide Prevention.

“I am hoping to carry on his legacy in this cause to bring awareness, the magnitude of the issue of suicide and how important it is to become aware of it,” D’Ulisse said.

The number for the Suicide Prevention Lifeline is 1-800-273-8255. The Out of the Darkness Walk takes place Sunday at 8:30 a.m. from the Art Museum to Martin Luther King Drive.

Some of the warning signs of suicide include people who talk about hurting themselves or describe being trapped in terrible emotional pain. Substance abuse, erratic behavior and sleeping a lot are also signs.

Stephanie Stahl