Latest analysis seems to point to Urartu as the culprit in the 800 BC destruction of Hasanlu...
http://news.yahoo.com/3-000-old-golden-bowl-hides-grisly-archaeological-110357626.html
Thanks for this, Dave. Once they have done the mineralogical analysis of the bones they should be able to tell whether these soldiers were invaders or natives; if the latter, we need to look for a different explanation for the city's demise - a natural catastrophe, perhaps.
Coincidentally, and quoting Michael Danti, the archaeologist at Boston University: "Hasanlu is sometimes described as the Pompeii of the ancient Near East, because of its so-called "burn layer," which contains more than 200 bodies preserved in ash and rubble."