As a garbageman, Brandon Olsen is no stranger to little kids excitedly waving hello as his truck pulls up to their homes. But as a father, the story of one little girl on his trash route broke his heart and inspired him and coworker Taylor Fritz to help.

Rosie Evenson of Blue Earth, Minnesota, who turns 4 this month, was diagnosed with stage 4 kidney cancer in September 2016. Rosie's mother, Angie Evenson, says all three of her daughters have, for years, had a standing date with their garbagemen every Thursday — when they gather in the window to wave hello to Olsen and Fritz as they collect their family's trash.

Rosie Evenson, 3, and her two sisters, Grace, 5, and Sophia, 2, wave at their garbagemen every week from their window. Angie Evenson

"They'd stop what they were doing and rush to the window to wave to the garbagemen," Evenson told TODAY Parents. "And the guys would always go way out of their way to wave big — you could tell they always made an intentional effort to look for the girls. We didn't even know each other's names at that point."

When their family moved to a different house in their small town, Evenson left a note for the pair, saying to look for her daughters at their new address. And, after locating their adoring fans in their new home, Olsen and Fritz delivered bags of Halloween treats to the girls last year, to thank them for their warm, weekly welcome.

Brandon Olsen and Taylor Fritz with their Hometown Sanitation garbage truck. Brandon Olsen

The following week, Olsen and Fritz received pictures drawn by the sisters, along with a heartbreaking note from Evenson explaining Rosie's diagnosis.

Trending stories,celebrity news and all the best of TODAY. This site is protected by recaptcha

"I just wanted them to know we weren't stopping waving at them," said Evenson, who, with her husband Aaron, has been taking Rosie for chemotherapy and radiation treatments that often fall on Thursdays.

The Evenson family: Aaron, Angie, Grace, 5, Rosie, 3, Sophia, 2, and Lincoln, 6 months. Angie Evenson

"I wrote a little note saying, 'Our little 3-year-old, Rosie, was diagnosed with cancer and has treatments on Thursdays, but keep looking for us even though sometimes we will be gone.'"

RELATED: Boy with cystic fibrosis becomes garbageman for a day

Olsen, who has three young children of his own, says when he read the note, he was devastated.

"This family forever changed my life — I read the note and was in near tears," said Olsen. "Being a father, it's scary to think, 'What if it were me in that situation?'"

Evenson says her daughter has had two surgeries, radiation and chemotherapy since September, when she began treatment for stage 4 kidney cancer. Angie Evenson

Olsen called Fritz to the front of the truck and showed him the note. The pair immediately began brainstorming ways they could help the family, and approached their boss, Mike Johnson, the general manager of Hometown Sanitation, to ask if they could donate their own free trash pick-up service — an employee benefit — to the Evenson family for a year.

"When Brandon and Taylor approached me with the letter that Angie had written and asked if they could donate their free service, I was immediately touched and wondered what we as a company could do to help," said Johnson, who spoke with one of his partners and decided Hometown Sanitation would donate one year of free garbage service to the family.

A picture painted by Rosie for her favorite garbagemen. Brandon Olsen

"We realize it's just a little bill," said Johnson. "But not having to worry about that one thing — we just thought that it might be helpful."

Olsen and Fritz presented the gift to the Evensons on behalf of their company, presenting her with a letter from "the Crew at Hometown Sanitation" that contained an encouraging message.

RELATED: 'It means so much': Little girl befriends garbageman, gives him a birthday cupcake

"As parents ourselves, we can only imagine what this is like for you," the letter read. "We want to wish you the best of luck as you fight on and battle through...stay strong, fight hard, stick together."

The letter written to the Evensons by Hometown Sanitation, explaining that the company would be providing them with free trash removal throughout 2017. Angie Evenson

Evenson says the act of kindness from Hometown Sanitation was one of many small acts that have given strength to her family during Rosie's treatment.

Never miss a parenting story with TODAY’s newsletters! Sign up here

"Everyone tells us, 'Oh, you're so strong.' But we feel so weak," said Evenson. "But the little things that people do carry you along, and it's kind of like you borrow the strength from other people."

"What they did made us feel like we were not alone," Evenson continued. "It was just a simple gesture, but to us, it was huge."

As Rosie's treatment nears an end, Evenson says she hopes her daughter will have some time to rest and recover from her procedures. Angie Evenson

With two major surgeries and several rounds of chemotherapy and radiation treatment behind her, Evenson says her daughter is about halfway through her cancer treatments. While some scenarios have Rosie finishing treatment in June 2017, there is a chance it will be an even longer road. The family has started a GoFundMe site to allow others to help with the expenses associated with Rosie's treatment.

So what do Rosie and her sisters think of their garbagemen and their act of kindness?

"To them, they are still just their friends the garbagemen," said Evenson. "And I love that their relationship has remained unchanged. I love the simplicity of the friendly smile and the wave — and, as a mother, I love seeing that there are still good people out there."