These two photos show the kenyan deadout that had the comb collapse. Most of the comb was on the bottom of the hive. It seems I had not fitted the usual batten under the roof which allows about an inch air gap between the roof board and the top bars. Therefore the roof board was in contact with the top bars. I will not make this mistake again. This loss was clearly my fault and is unfortunate that it probably happened when the heat of summer usually meant drones had already gone and brood rearing had slowed or stopped. The new combs shows me that the bees tried to rebuild and tried to raise new drones when the queen was lost.