Steps to reproduce:
1. Create colony with functional water/housing/food supplies
2. Disable all water/housing/food-related buildings
3. Allow storages to drain
Colonists don't die and still reproduce babies, even when there is no water, no food, and nowhere near sufficient housing.
This may be related to the health freezing bug: health is also frozen in the colony in which this bug appeared.
I've attached my broken colony here: