Yes, there are quite a few. Some 'peggy dies civil war fanfic' stories are very popular among fans. You can check out fanfiction platforms like Archive of Our Own. There you'll find different interpretations of this scenario in the context of the Civil War universe.
In the fanfic world, the public's reaction would be huge. Spiderman was a beloved hero. There could be mass protests against the superheroes and the Civil War in general. The remaining superheroes would have to deal with this public outcry while also mourning the loss of Spiderman. They might also start to question their own actions and the future of superhero - ing without him.
Well, one way could be that in the chaos of the Civil War, Spiderman might be caught in the crossfire between the two sides. Maybe he tries to stop a particularly violent clash and gets overpowered by the combined forces accidentally. Another possibility is that he's betrayed by someone he trusts on one of the sides, leading to his demise.
There are a few significant deaths. One of them is Goliath, who is tragically killed during the battle. Also, some minor characters lose their lives, but their impact is relatively smaller compared to major ones.
Well, if Spider - Man died in a Civil War fanfiction, it could be that his death serves as a catalyst for the end of the war. His death might make both sides realize how pointless their fighting is. Maybe the heroes would then come together to honor his memory and try to make amends. His friends in the superhero community, like Ned if he knew about Peter's identity, would be heartbroken. And villains might take advantage of the situation, thinking the heroes are weakened without Spider - Man, which could lead to new threats emerging in the fanfiction world.
The Captain America: Civil War comic doesn't feature a lot of prominent character deaths. It's more about the ideological divide and the battles that ensue rather than major fatalities. Some lesser-known characters might be killed off to add tension and drama.