Where troops have only a single Wound, casualties are removed as follows. If a unit of troops is hit and suffers wounds that it does not save, then, for each wound suffered, one model is removed as a 'kill'. Individual warriors are not necessarily dead, they may just be too badly wounded to fight on. For our purposes, the result is the same so we treat all casualties as if they were killed and remove them.
Although casualties would really fall amongst the front rank, for the purposes of game play remove models from the rear rank of the unit. This keeps the formation neat and represents rear rankers stepping forward to cover gaps in the line. If the unit is deployed in a single rank, then casualties are removed equally from both ends.
Suffering casualties may cause a Panic test as described in the Psychology section.