The Jarl's wizard just up and died on me...?

This is certainly odd... I tried pickpocketing Jarl Balgruuf's wizard while he was sleeping, but got caught. This time, I decided to have my first stay in prison, just for the fun of it. Picking the lock failed, so I slept off my sentence. As soon as I got out, I see some guy running up the steps to the castle... it's a messenger, and he delivers me 90 gold (after tax), and a letter stating that it's my inheritance from the wizard, who apparently passed on during my jail stay.

What the hell happened? I've looked up his character on the wiki, and apparently he's needed in some future quests. Was it a bug? Do random deaths occur like that? Is my save screwed?

Solution 1:

Did you have a follower with you when you were pickpocketing? If Farengar caught you and went aggressive on you, your follower would have attacked Farengar and would have easily killed him. Farengar is a terrible fighter and is not an essential.

If you did not have a follower, perhaps a guard or another person in the vicinity witnessed Farengar attacking you and attacked the aggressor.

Solution 2:

I don't think there really is a way to know what happened, considering all the funky stuff that could happen in Skyrim. I don't believe those deaths occur randomly (Like, drop dead in the middle of the street random. It's still possible for NPCs to be slaughtered by a random dragon). You'd be better off reloading to an earlier save.