re: If you accidentally started a fire, and someone dies as a result, are you respon

No, you would not be guilty of murder, that requires intent. The most you could be charged with is negligent homicide and even that would require criminal negligence, i.e. a "reasonable person" wouldn't have been that much of a dumbass.

My guess is that you would not be criminally charged but the family of the deceased would sue you for everything you have and hopefully you have good insurance.