Rally at 0

[Lt. Ketch]

I've had a varity of units' rally scores drop to 0 in the middle of a battle. What causes this happen? Is it possible for that unit's rally score to return to the initial value?

Particulars - This has happened in my Russian LC (current date - 11/41), more prevently in my support units, but has also happened in the core. The units have been primarily infantry but include: rifle squads, MMG squad, and most recently Ski pioneer. They have be units of platoons that have lost the platoon HQ (i.e. B0), the HQ unit themselves (which really bites), or just a unit in a otherwise healthy squad. Almost extensivly they have been units which have come under heavy fire, primarily from close quarters as well as units that have close assaulted tanks. I can guess that these conditions may have a heavy influence on my situation, but I'm looking for a more extensive explination.