As far as the number of bees lost, my experienced beekeeper felt that out of around 11,000, at least a third were gone. We opened the hive at noon and some of them could have been out but that many? I had counted 25 dead bees in front of the hive three days ago and when we opened the hive, there were at least that many more dead on the bottom screen. I assumed that was a bad sign as well since bees usually keep the hive clean.
I used a wax foundation. I wish I could describe how they drew it out but it wasn't like all the examples I have seen where the cells are flush with the frame. This was more of a layered deal and there were bees walking underneath the cells they had drawn out. I hope that makes more sense. There were a few places on the frames where the foundation had been drawn out correctly but there was nothing in those cells.
Other cells contained eggs and pollen but all of the larva appeared to be dark brown and my beekeeper said they were dead.
Our weather has been all over the map since the installation. A few nights have been in the 30's and the days have ranged from the low 40's to the upper 60's.
There were only two frames that had small clusters of bees working away. We weren't able to locate the queen, despite the small numbers.
My beekeeping expert thinks my hive is probably going to keep sliding downhill. I had noticed mid-week that the activity level had changed drastically, especially considering that it was a lovely warm day, the same as the previous two during which the bees were all over.
Hope this helps give you a better idea for diagnosis.