So I went to buy and sell from the black smith in whitrun and both her and her husband are dead I'm not sure how this happend I am curious if anyone has had the same thing happen??

I had a guard turn up dead in Whiterun.
I believe other forum members have reported more unexplained deads.

It happens, I guess.

You probably walked into town with a disease, and killed them by being the carrier.

No, it doesn't really work that way.

I've heard of stuff like this, but I have never actually seen it happen except for once. I was walking through Windhelm once and I happened upon three guards dead in the street, so I don't know what the heck happened. My bet? Someone went crazy, or the AI messed up and the people were flagged as enemies and butchered.

I watched the Blacksmith and his wife and the Storekeeper and his sister all die together by dragon breath when one attacked the first village you go to after getting out of Helgen.

The 4 bodies are still lying there 51 levels later!

Dragon attack? Unless you want to reload an earlier save I reccomend stripping them all and promptly moving into their home. Then you too can become a self obsessed biatch with second rate weapons and a pvssywhipped husband!