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Why Charlie Barnett Left Chicago Fire After 3 Seasons (But Wasn't Killed Off)

The actor played the beloved Peter Mills from the jump of the show. 

By Jackie Manno

Chicago Fire saw a major plot twist at the end of Season 3 when firefighter Peter Mills (Charlie Barnett) gave up his career to be with his family in North Carolina, leaving the show without one of its primary characters. But why, exactly, did the writers choose this path for Mills?

Why did Charlie Barnett leave Chicago Fire

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In a 2015 interview with TV Guide, former Chicago Fire executive producer Matt Olmstead explained the reasoning behind this decision. Ultimately, Mills' storyline felt complete, and showrunners thought it was time to make room for new characters. 

"The hardest part of this job is when you feel it's the right time to make cast changes. It was solely based on bringing in new people for new stories. Otherwise it turns into a clown car. You have affection and admiration for [your cast], so you keep everybody, but it's at the detriment at being objective and making some tough calls in terms of storytelling. So, we wanted to shake things up and bring in a new character and we started discussing the idea ... and here we are. It was an extremely tough decision to make, but we feel good about it," Olmstead said. 

Olmstead then explained why Mills moved away to another state instead of having the character die in the show, like many often do. 

Peter Mills (Charlie Barnett) appears in Chicago Fire.

"His departure goes towards the original mythology we gave the character, which is that he had a dad die on the squad and his mom and sister had a restaurant. He worked at the restaurant and his mom didn't want him to be on the squad anymore, and he was pulled in two directions. Ultimately, he makes the determination that he fulfilled his father's legacy to the extent that he wanted to and he could check that box in terms of walking in the footsteps of his father who he never really knew," Olmstead added. 

Meanwhile, Mills' partner at the time, Sylvie Brett (Kara Killmer), was shaken up by the whole ordeal.

"She takes it the hardest — he was her first real partner," Olmstead said. "And she's not a thick-skinned, jaded paramedic who's been doing this a long time. She came from the sticks and she's still learning, so it hits her hard." 

RELATED: Monica Raymund Reveals the Very Relatable Reason She Left Chicago Fire

Barnett completely understood the decision and thinks fondly of his time on Chicago Fire. "I got so much from the show, the connections, the family we created," he told the Sarasota Herald-Tribune, according to Looper. "It is beyond special and will never go away. I learned so much about myself as an actor, about the business and what direction I want to go in, so it will always be a part of my backbone."