Actually, I'm in California---however, we had this early "False Spring" with
temperatures in the '70's, then this cold storm suddenly came in, and the
temperatures rapidly dropped into the high 20's/low 30's at night, where
they stayed for about a week.  (There was snow lasting below 2000 feet for
over a week---something I've never seen before in this area.)  Sounds like
the warm weather geared them up, then dropped a cold shroud on the colony.
Thanks.  It sounds very probable.
 
  -Jane