Cause of death?

[Dornfield]

I saw a deformed developing pupa being dragged out of and away from the hive today: bulbous head/ thorax which upon poking with a dry grass 'stick' appeared to be gas filled (compressible without 'bursting' rather than liquid or foul). Are here any tell tail signs on the attached picture that would indicate what has caused the death of this developing bee and whether I should be concerned? The picture is a little overexposed.

Thanks as always.

Dornfield