What has happened to Huck's father?

Huck Finn's father died in the book. When Huck and Jim are floating down the river in their raft thing they come across an actual house floating down the river. So they board the house to find some supplies and things, and Jim finds a dead guy in the bedroom and tells Huck to not come over and see him cause the body is "too bloodied up" and gross. But really, jim knows that its Huck's father. He doesn't tell Huck this because he fears Huck will want to return home and Jim wants to sail to freedom. Nobody really knows who killed him haha sorry. I'm pretty sure he was just drunk one night and got shot or something.