Death in game: Does life go on or do you revive your sims?

How you describe it, I think it would be best to roll back a save. This sim seems to be important to you and you seem to have plans for them. I decide from case to case. Sometimes I just accept what happened and go on with it. For example: I had a happy couple and he died of electrocution. After she finished grieving, she moved to a different world and got to know somebody else. But sometimes when the sim ist very important to me or I have plans for that sim, I roll back a save.