The community is rallying around a St. Paul police sergeant battling stage four cancer.

Don Grundhauser got the life-changing diagnosis in July — stage four colon cancer.

“I want to wake up some mornings and say this is all a dream,” said Don. “I mean, I’m a realist but you just don’t want to lose hope; you just gotta keep fighting forward.”

He’s a familiar face in the community after three decades as a police officer, serving on the SWAT team, gang unit and special operations.

“You always ask yourself, ‘Did I make a difference?’ Don said. “You want to feel like you did.”

Don not only inspired his two younger brothers to join the department, but also his son, who now patrols with his dad’s old badge number.

“He’s a special person; he means a lot to everybody in our city that he has helped and this is a way for us to pay that back,” said Mike Ernster, former public information officer with the St. Paul Police Department.

Loved ones are hosting “Grundy’s Day” on Saturday to raise money for his medical expenses and he was even honored at the State Capitol on Thursday.

He not only helped the community as a cop but also with his cancer story, reaching friends, family and even strangers.

“They went and decided to get that colonoscopy and found early cancer, so that’s the silver lining in some of this… it may not be the silver lining for him, but the fact that again he’s making a difference,” said his wife, Kelly Grundhauser.

Don’s cancer didn’t respond to 12 rounds of chemo — he started a clinical trial this week and says no matter what lies ahead, he’s grateful.

“I mean, I’ve had people reach out to me that I’ve arrested before to thank me because I treated them right, and that means a lot and they’re praying for me and it’s just, I don’t know, it does, it touches you; it goes back to you feel like you made a difference,” Grundhauser added.

St. Paul Police Chief Axel Henry told 5 EYEWITNESS NEWS:

“Don’s life and career has been a model of service. His entire family has dedicated themselves to helping and serving others. On top of all that, he is one of the most popular and liked employees our department has ever had – and we’ve had a lot of great people. The entire department stands behind him in his fight against cancer.”

A fundraiser for Don is running from 1 p.m. to 6 p.m. on Saturday at the Earl & Wilson Event Center in St. Paul.