So I was fighting against the Blood Dragon at the Western Watchtower, when suddenly another, normal Dragon appeared. Along with a flaming carriage. When I killed both of the Dragons, I went to check the carriage. It was lying on its side, near the destroyed and abandoned farmhouse, between the Watchtower and Fort Greymoor. And there were three corpses near the cart: an Imperial male and -female and high elf male. They were in normal clothes, so no Thalmor and Imperial Soldiers.
Has anyone else encountered this? I play on PS3, so no mods.