im putting all the details we have on the story into this!!!! it's basically just how everyone died and what happened afterwards, but all u need to know is that its like,,,, one incident after another.
anyways, izuku was the first to die. It's in some sort of incident, where he gets separated from his classmates and sm heroes(its implied theres a battle going on) and gets killed by villains. He bleeds out like,,, just as people show up. From there, Izuku wakes up a pool of his own blood and spends a few months in the wild before he joins a group. then todoroki shows up, he gets dragged off, they get separated, and Izuku joins snowbound. Izuku has been a cat for about,,, four, five months?? however, the timeline is very messy. like, somebody killed at the end of the timeline could have woken up before izuku(not recommended tho afdsfds)
anyways, during that battle, a few people could have died after izuku? doesnt really matter to me, but none died before izuku, at least.
todoroki dies a few weeks later. apparently the class 'stopped caring' abt izuku's death a few weeks later(do what u want w that), and goes to seek revenge on the villains. it goes well until they call backup, and then todoroki just. dies. todoroki gets reincarnated. the house burns down and he meets izuku, who does his best to help. later, todoroki drags izuku away from his current group and they travel for a while up until they get separated. He recently showed back up, though.
bakugou is killed by toga disguised as kirishima, death by stabbing. he wakes up in a puddle of blood.
tsuyu dies by electrocution after trying to swim tokoyami to shore during a villain attack. the villain had a electric quirk, and tsuyu, being weak to such, died on impact when she was shocked. she then sunk to the bottom of the body of water she died in. tokoyami died by drowning in this same incident, passing out from the electrocution and instead drowning.
mirio and tamaki had both died at the same spot, on the same day. mirio had taken on a villain much too strong for him in the city, and had been crushed to death and died on impact. tamaki, angry at the villain for killing mirio, also went after him. he soon died as well, leaving the two to die together.
dabi died after picking a fight with hawks and endeavor, getting too cocky before he died by being sliced through the heart by one of hawk's feathers.
but we do have aizawa!! his is like,,, extra vague. aizawa's death takes place at the v v end of the timeline, and is basically the 'end all' where the remaining characters die lmao. this is like,,, the vaguest part of the timeline bc aizawa doesnt remember(and guts doesnt have anything to add lmao), but smthing happened, and aizawa couldnt save the remaining students i guess. anyways, aizawa, like izuku, wakes up covered in blood, but is found promptly by izuku, and joins snowbound.