Black honeycomb

I recently visited my grandfather's hives to help him close them up for the
winter (North-central Pennsylvania).  One hive was a Russian hybrid which
has done ok but nothing spectacular - they filled 1 medium super since
they've been there (May 2003).  The other hive was a Minnesota hybrid which,
from day one, never did anything.  We tried feeders and raw pollen -
nothing.  When I opened the hive this past weekend - a large group of bees
were drowned in the frame feeder and there were NO live bees - every single
one of the brood had left - no chalkbrood or anything but the odd part was
all of the honeycomb was black - any ideas?

Thanks

Marc Wachter
Bluebird Hill Apiaries