Hive collapsed, trying to figure out what went wrong
So my hive either absconded or had a deadout from varroa, but I'm not sure. It was very sudden. There was some very heavy robbing behavior last weekend and I reduced the entrance, closed the hive, etc. but did not do an inspection for fear of starting a frenzy. Didn't matter anyway, they were already gone. Here are the photos I took today:
Capped honey mostly intact aside from the robbers. Very few capped brood and what there was did not look good. I noticed that some of them were "stringy" so could it be foulbrood? I intend to contact my local beekeeper's association to get a more expert opinion/look. I did a mite count in July and it was 3 mites/cup of bees using alcohol wash, but did not do another test since, which was not very smart of me. For reference, the hive frames mostly look like these exactly a month ago (end of August):
I didn't take any photos from my last inspection (first week of September), but there were fewer brood frames than the August inspection. I really, really would hate it to be foulbrood because this is my first hive since I stopped keeping 5 years ago. I'd like to re-use the frames and be smarter next time, but it'd be a shame if I had to burn all my equipment. I'm pretty sure it's varroa, but I'm not experienced enough to make the call.