New Season of bees

I again have 4 hives this year, didn't have any survive last winter...which is my #1 goal this coming year. I left plenty of honey for their winter food but I dont think there were enough bees to cluster and stay warm enough to make it through the long winter here in seattle.
Anyway on april 19th, I hived the 4 new packages and left the queens in their little cages so the bees could get acquainted with them, and improve acceptance. A week later it was time to release the queens. My friend who hosts the Admiral hive discovered my queen, dead in her cage :-( The other three hives were just fine, so not sure what happened there...
I got a replacement queen- under "warranty" as a result of this death, so early after receipt.
I will go back and let her out this weekend, and check the other hives to make sure the queens that did live are laying eggs.