Among the advertisements lining the billboards along a stretch of road in Kansas City, Missouri, is one with a simple yet powerful message:

"You are human. You are loveable. You are strong. You are enough."

Nicole Leth rented the billboard in honor of her father, Richard, who died by suicide when she was 17 years old.

Nicole Leth rented a billboard in Kansas City, Missouri, to spread positive affirmations in honor of her father, Richard, who died by suicide when she was a teenager. Courtesy of Caroline Adams

"It launched me on this trajectory of wanting to do things that matter to people and have positive output to what I created with my artwork and writing," Leth, now 26, told TODAY.

"I realized over the years I could never save someone’s life for them, but I could create an encouraging and affirmative space to empower them to save their own life."

In the nine years since she lost her dad, Leth has found comfort in spreading positive messages, but had never done anything this public until now.

Nicole Leth as a child, holding hands with her father, Richard. Courtesy of Nicole Leth

“I started putting affirmations on stickers and leaving them in public spaces, giving them to teachers, sending them in the mail and letting them go into the world where people could discover them in ways they need them," she said.

Two months ago, she decided it was the right time to take her message of hope and amplify it. That's when Leth, who is an artist, designed the billboard and paid for it to run for one month.

“I wanted to take the affirmations and make them louder," she said.

Her message has resonated with everyone who sees it — and has gone viral.

"He truly had the same heart as me," Nicole Leth said of her dad. Courtesy of Nicole Leth

“The reaction has been unbelievable and heartfelt and overwhelmingly positive," Leth said. "I have been receiving lots of emails from people who said it mattered, or they saw it and had a terrible day and didn’t think they could survive, and without knowing the story of the billboard, they said it let them live one more day."

Other people who have lost someone to suicide told Leth the billboard shares the words they wish they could have said to their loved ones.

While she initially paid for the billboard to run through mid-August, Leth said the owner of the space has been touched by the response and emailed her to say it will run free of charge for the foreseeable future.

Leth said she has shared the artwork with people who plan to rent billboards in Vancouver, Canada, Orlando, Florida, Des Moines, Iowa, Springfield, Missouri, and in Texas.

It's the perfect way to honor her father and spread a message of hope she said she knows he'd love.

"He truly had the same heart as me and he always felt things so intensely. We’d always go on these cross country road trips and have the deepest conversations about life and people and love," she said. "He was the first person who taught me how to make beauty out of hard things."