For me its a common thibg. Whenever i fast travel to Riften or Dawnstar (usually Dawnstar) a Blood Dragon always shows up and kills off few people. Its so annoying..
And today 4 qyeat people were killed in the proces during the Dragon attack on Riften. If i didnt reload the autosave i would have lost an opportubity of buying a house because one of the jarl's people got killed. Dont remember her name but she got killed. I reloade the autosave and killed the dragon before it could do any damage. I was just lucky on my second try. (i just know where its going to attack XD) phew!
But really.. The random dragon attacks are seriously getting under my skin

'
Im getting aick of them
(still hoping to meet an ancient or elder dragon XD
I'm level 31 now. Nearly 32.