"I am going with nosema on that one. They were pooping on the top bars and on the sugar cake. It takes a bit to make a bee do that in its dining room. Usually you see it mostly by the upper entrance where they tried to make it out and didnt quite get there... Or just outside that entrance and all over the front of the hive... As opposed to just letting it go RIGHT where they are, That usually meant to me that they were in pretty serious trouble."
what scott said ted, one of the nosemas........
this is evident from what scott said about the top bars and on the sugar cake, also, a smaller cluster. just a note, even though we find dead bees with heads in cells does not mean they died of starvation........bees crawl into cells in cluster.
as far as cleanup, like cbt and scott said, scrape the tops of the frames off and if need be use bleach.......a 50/50 bleach wipe down. frame faces: if the honey frames are capped, a quick wipe down. it they are not, ditch it.