SAN DIEGO (KGTV) — After more than three decades working with Cal Fire in San Diego County, Battalion Chief Kari Thompson described her retirement with mixed emotions: excited, sad and happy all at once.

Thompson always knew she wanted to work in public safety. Her stepfather worked in a Southern California sheriff’s department. It was an introduction to a fire explorer program in high school that changed her life.

“I liked that it was physical, challenging, and then something that I could give back,” Thompson said during an interview with ABC 10News anchor Melissa Mecija.

Looking back on her career, Thompson acknowledged the challenges she faced over the years.

“Even my mom was like, ‘Are you sure this is what you want to do?’ She thought maybe it was just a phase,” Thompson said. “My stepdad had told me … you’re getting into a male-dominant field, and so are you going to be ready for that?”

Despite the naysayers, Thompson proved herself and rose through the ranks.

“It’s been nice to be able to be a role model for other women,” she said. “People have this misconception that you have to be this big, bulky person when it’s technique really … and determination.”

As she reflected on her time in the fire service, one major incident that stood out in her 31-year-career was the 2007 Harris Fire.

“It was probably the windiest days that I had seen leading up to that incident,” I was the first arriving engine on that fire. That probably is the most impactful incident to date to my career. Something I’ll never, never forget.

While her crew’s actions saved numerous lives, Thompson still thinks about those who could not be saved. The Harris Fire, along with several others burning in San Diego County at the same time, consumed more than 349,000 acres and destroyed roughly 1,600 homes. 10 people died.

“That was hard to live with for a long time. It’s something that haunts me … What if we had done this? What if I’d done this different?” Thompson said, as she got emotional thinking about the devastation.

Despite the difficulties throughout her years in the fire service, Thompson never regretted her career choice.

Thompson represents a rarity. Of the roughly 1,000 personnel in Cal Fire in San Diego, she is one of about only 20 women. According to Cal Fire officials, she is the most senior female in the Southern California region.

When asked about colleagues praising her leadership and role model status, Thompson held back tears, saying it made her proud.

“This is really all I’ve known since I was 15 so that’s the hard part, but that’s the part that makes me happy too,” she said. Thompson takes pride in seeing former firefighters under her command advance in their careers, including one who now outranks her.

“People that used to work for me, and now I work for them. That’s the happy part. ” Thompson said.

Thompson plans to stay busy in retirement. She has completed 16 Ironman competitions, including one in her full fire gear while carrying an American flag.

“For next year, I already signed up for four races to keep myself active. That’s part of my retirement plan. My husband just asked that I don’t race like every month,” Thompson laughed.

Her husband also retired from Cal Fire. They both look forward to spending time with their adult children, including one currently in college playing baseball.

As she gets ready to call it a career, Thompson wants to thank the people of San Diego County. “It was an honor, and I really enjoyed it,” Thompson said.

Her last day is December 4.