Absconded Bees

So I talked to my father tonight. The second hive of the bees we purchased this year absconded.

(For those of you not in the know, swarming is when a colony splits, absconding is when the whole colony moves out).

I am quite depressed about the whole thing - two weeks ago, when I looked, the colony seemed fine. It's as if nature itself is fighting against me. What don't I know? What I've read suggests it is due to major stress such as bears, starvation, weather changed, etc.

Not sure - but it sure is disappointing.