I caught a very small swarm a while back and had little hope that they would make it. When I collected them they had been out in the rain and the cold for a week exposed. I was pretty surprised that they then picked up and built comb, had a laying queen and were making progress. I just went away for 10 days and during that time this small but active colony totally died.
They left 4 combs of wax
There was plenty of capped brood ready to emerge (some dead in the process of emerging)
about 6 dead bees visible in the bottom of the hive
Some eggs visible in the bottom of cells.
All honey stores have been stripped out by my other colonies
WHile I have been away I have had reports of a swarm of bees in the area that went into a roof, absconded, went into another roof and absconded again.
My thoughts are that they have absconded rather than died (my adjacent hive is going gangbusters so I'm not thinking about pesticides).
Moderator, Treatment Free Beekeepers group on Facebook.