Bee loss with cloake board

[brendan]

I just experienced a significant bee loss in a hive I am trying too raise queens from. I rotated the 2 deep hive 180 degrees so the entrance was facing the rear and placed the cloake board between the two supers with the new entrance facing the front. I blocked off the original entrance (now facing the rear). The queen is confined to the lower box. I put in some fresh comb hoping to get her to lay in it to make queen cells with the hopkins method. I returned 4 d later to see about 1-2 inches of bee coprses on the screened bottom board.
The queen is alive with a good amount of bees but she didnt lay in my new comb.
Any ideas on the die off? This was not mentioned in my reading about the cloake board. Anyone had this happen. Whats going on

[Michael Bush]

I never close off bees without a very good reason.  The die off is the field workers frantically trying to get out...  Just turn it around, as you did, and those field bees would have left and come back to the top...

[jdpro5010]

I would say closing off the entrance was the cause.  I use the Cloake Board Method and never had a problem.  I will also add that it would have created some ventilation issues that may have created the problem.