[Warning: this post contains spoilers from Chicago Fire's Season 8 premiere. Read at your own risk.]

Tragedy is nothing new for Chicago Fire, but Wednesday's devastating premiere delivered a real kick to the gut. The Dick Wolf drama returned for Season 8 with an emotional hour that saw the firehouse lose one of its own in one of the show's most heartbreaking season openers to date. Seriously, this one really stung.

The episode, titled "Sacred Ground," picked up immediately after the events of the Season 7 finale, with most of Truck 81 trapped in a warehouse basement fire and right in the path of an old industrial boiler that blew up seconds later. Despite the danger, most of the crew ultimately walked away unharmed, including Casey (Jesse Spencer), Severide (Taylor Kinney), Herrmann (David Eigenberg), Mouch (Christian Stolte), Cruz (Joe Minoso), Foster (Annie Ilonzeh), Ritter (Daniel Kyri), Kidd (Miranda Rae Mayo), and Boden (Eamonn Walker), while Brett (Kara Killmer) sustained a serious arm injury from heavy debris that fell on her. Unfortunately, Otis (Yuri Sardarov), who was closest to the explosion, suffered severe burns to the face and neck and later succumbed to those injuries.

Otis's tragic passing left the entire firehouse reeling, especially Cruz, who struggled to cope with the loss of his best friend. To honor his memory, Boden erected a statue in Otis's name and declared the fire station sacred ground. His death is a tough blow that, according to showrunner Derek Haas, will have ripple effects throughout the season. TV Guide caught up with the Chicago Fire boss to discuss what's next for Firehouse 51 following Otis's death, including the arrival of a new firefighter and how everyone will continue to grieve.

Jesse Spencer, <em>Chicago Fire</em>Jesse Spencer, Chicago Fire

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Tragedy struck the firehouse, with Otis perishing in that warehouse explosion. What went into the decision to kill him off?
Derek Haas:
We finished the season not knowing what we were going to do past the finale. I was talking with our head writers, Michael Gilvary and Andrea Newman, about how, so many times, shows like ours pull the punches. You put everyone in jeopardy and then you miraculously get out of it. We're as guilty of it as anyone, but you can only pull the rug out from under the audience so many times before they just don't trust the suspense anymore; they don't trust the danger. I think our show has on occasion proved them wrong, where there is a real effect to a tragic, dangerous situation, and we just felt like it was time to do it again. We settled on it being Otis, and I called Yuri [Sardarov], who could not be a more professional, great colleague, and told him what we were thinking. As you would expect from him, he thanked us profusely for the seven years he had on the show. I told him what the storyline was going to be, and he really got behind it and agreed to come back and do the first episode.

With Otis gone, how will the firehouse try to fill the void that he leaves behind?
Haas:
We've made that a priority in this season that it's not just something that happens in the first episode and we forget about it. There are going to be be effects throughout the season. We thought what would be interesting this time [is to explore] how the tragedy affects different people in different ways. The way it affects Cruz is not going to be the same way it affects Mouch or the way it affects Severide or Boden and Casey. And so we're going to play those tense roles throughout the season.

What's the deal with new paramedic Chad Collins and how long is this guy sticking around?
Haas:
This isn't the last you'll see of him. You're going to see more. He's a free spirit who is very confident in himself, perhaps unmerited. And so he's a little bit of a thorn in Foster's side, and we wanted to contrast how great of a partner and friend Brett is versus this guy who's taking her place.

Brett got engaged to Chaplain Kyle (Teddy Sears) and moved back home to Indiana. Do you think she's completely happy there, or does she have some reservations about leaving Firehouse 51?
Haas:
I think you can tell in the first episode that there are some reservations and just looking at the future saying, "Is this going to be the life that I'm going to have from now on?" And [asking] was she perhaps a little rash in reacting the way she did to Kyle's proposal. A lot of people expected us to resolve that quickly at the beginning of the season, and we wanted to say, "No, our show's not like that. We don't just reset back. We have to have consequences to these actions." So this is going to play out a little bit.

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Last season, you hinted at a romance between Brett and Casey. Are there still some lingering feelings between the two or have they both fully moved on from that?
Haas:
With two people who work together, that's never going to exactly go away. Nothing has been requited at this point, so that's got room to grow if that's where we determine that it's going to go. But right now, she's in Indiana with Kyle, and I just loved the opportunity to bring Hope (Eloise Mumford) back.

We know that newcomer Blake Gallow (played by Shadowhunters' Alberto Rosende) is headed to the firehouse. What can you tell me about him?
Haas: You're going to meet him in the next episode. He has a very dramatic introduction to the show... He's like raw energy that Casey latches onto and realizes maybe this is what the firehouse needs, sort of a diamond in the rough. He's almost the combination of a young Casey and a young Severide; he's got a little bit of both of their personalities. You can kind of see where his career trajectory would go if he has the right people mentoring him, so that's where we're headed.

This year, you're writing all three crossover episodes, so what was that like?
Haas:
Dick [Wolf] and I came up with the story, and we outlined the three episodes. I wrote the first one and we staggered the productions so I could write all three, which was the plan. And then reality set in as it just became bigger and bigger, and Andy [Schneider] and Diane [Frolov] ended up writing the middle episode and then Gwen [Sigan] wrote the P.D. episode. I wrote the story with Dick for all three but only ended up writing the first episode.

What can you tell me about the circumstances that bring these three departments together this time?
Haas:
It's going to be madness. There's an outbreak of a really bad bacterial infection that's going to be infecting lots of the city and of course, they're going to need all three first responder units to deal with it. I think the biggest difference between this one and the other ones we've done is that while it'll feel like a Fire episode and then a Med episode and then a P.D. episode, at the same time, there's way more of all three shows in all three hours, so it's really like a special event.

Chicago Fire airs Wednesdays at 9/8c on NBC.

Eamonn Walker, <em>Chicago Fire</em>Eamonn Walker, Chicago Fire