Golf Pro Killed with 3 Kids in Plane Crash Was Someone Who Could 'Make You Dream for More': Friend

"If you told him your dreams, he would one-up them and make you dream for more," Shelby Hunt tells PEOPLE of Sean Fredrickson

From left: Shelby Hunt and Sean Fredrickson. Photo: Shelby Hunt

Sean Fredrickson — who was killed with his three children in a plane crash this weekend — strove to bring out the best in those around him, his longtime friend Shelby Hunt tells PEOPLE.

Like so many others at Oswego Lake Country Club in Oregon, 24-year-old Hunt is still struggling with the death of Fredrickson, the club's beloved head golf professional.

The 48-year-old father was visiting Lake Coeur d’Alene with his family on Sunday when the seaplane he was in collided with another aircraft. The crash also killed Fredrickson's 16-year-old son, Hayden, and his two stepchildren — Sofia Olsen, 15, and Quinn Olsen, 11.

"As time went on, it's not that we didn't lose hope, it just shifted to hoping they were all at peace and that they got to be together," Hunt, an assistant golf professional at Oswego, says of receiving news of the crash from Fredrickson's wife, April.

"Then after seeing the photos and knowing that the four of them were together ... I know how much Sean loved his kids, that that's right where they would have wanted to be," Quinn tells PEOPLE.

An investigation into the crash is ongoing.

Sean Fredrickson and his children Sofie, Quinn and Hayden (L-R). Facebook

Fredrickson rarely took time off from the club and the trip to the lake was a rare summer excursion for the family, Hunt says.

"Sean always had vacation time that he just never used," she recalls. "Every December he would finally take his vacation before it would expire — and the entire time he would be texting everyone at work, asking how things were going, because he just was really here."

"In spirit, he was always here," Hunt says. "It didn't matter where he was. He was always checking in on us and making sure things were running smoothly. His work was his baby."

Hunt first witnessed Fredrickson's dedication to golf when they crossed paths at a tournament in 2014, shortly after she graduated high school. He took such a liking to Hunt that he challenged her to a game of golf.

If she could beat him, he'd take her under his wing and offer her a job (the game went down to the 18th hole).

"He wanted you to feel proud of what you did," Hunt says of Fredrickson, who became a mentor to her. "If you told him your dreams, he would one-up them and make you dream for more. He was someone who believed in you more than you believed in yourself."

Shelby Hunt

As Hunt and Fredrickson's bond grew stronger, so did her relationship with his family, she says. She often babysat Sofie and Quinn and sometimes watched Hayden when he was younger.

"Sofie was the social butterfly," Hunt says of Fredrickson's step-daughter. "Every time I would get to her house, the doorbell would ring or someone would sneak in to hang out with her. She had so many friends."

"Quinn was a huge Star Wars fan. We called him the little nerdy one," Hunt continues. "He had every Lego you could possibly buy at the store, and he had them all assembled in his room and he always wanted to show you. He wanted to show you how to put it together, so he would take it apart."

"Hayden was just so down-to-earth," Hunt adds of Fredrickson's son. "He was very social, and he always was trying to learn something. I know Sean was so proud of him on and off the soccer field."

April and Sean Fredrickson. courtesy april fredrickson

Hunt says the past few days have been "really hard," and she is still working through her grief.

On Tuesday night, she scrolled through the messages Fredrickson sent her over the years, from recent texts to ones sent back in 2014.

"I just read those messages from him and reminisced on all the things that he had planned, not only for his future but for mine, and it's something that I'll be forever grateful for," she says.

Though so much of her life had revolved around golf, Hunt recently told Fredrickson she wanted to switch paths and become a nurse. He was one of the first people she told because she knew it would be difficult for him to hear.

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But after Fredrickson's death, Hunt says she's had a change of heart.

"I don't think I can give up on his legacy," she says. "I know what he had planned for golf, and I know what he was doing.

"I want to be a part of that forever," Hunt adds. "He did amazing things."