(I know this was an old post, but I haven't been on for a while. It's a long post, read at your own risk...)
Ack! Once again, I can't say with 100% certainty, but I've never encountered a "sudden death" or "mass death" BUG in any games (ever!). It was always (!!!) due to resource mismanagement!
Just because Wiki says it doesn't mean it true.
Unfortunately, the way OP1 calculates and displays resources can mislead you into thinking you have enough food/metals when you don't! There is no bug, but many people experience mass death around 50 or 100 turns (coinciding with the death of several initial structures).
Things I've encountered which led to colony loss:
-Seed smelter quits for some reason. (Might be a bug). It just decides it doesn't want to process ore anymore or it isn't being sent to the storage tanks (stacks up in the smelter). This means the resources aren't getting to the important buildings (CHAP, agridomes...)
-Expanding a mine too early. If you only have one mine and you dig it deeper, it stops producing for 7 (I think) turns. What this means is if you don't have enough resources built up, your important buildings will, once again, run out of resources.
-There aren't enough agridomes for the colony. i.e. you have 201 colonists but only 2 agridomes. That 1 colonist will eat up 1 food unit (while the other 200 take up 20). Which means that if you don't have enough stored up before you get Agridome #3 built, your people WILL starve (all of them!!!!!, not just the 1 extra dude!) Once they start dying, it's hard to make them stop even though you will have several turns where there is plenty of food. I know, you'll say "But I click on resources and I have 20 units of food in storage." Right, but that's AFTER everyone has eaten (and starved) because you only had 20 last time. And you'll only have 20 next time. You need 21 for people not to starve (if you have 201 colonists). Morale plummets and colonists end up in a death spiral, typically with no recovery...
-Digging your only underground tube deeper. If you only have 1 shaft down to the lower levels and decide to make it deeper, your colonists will start dying because they will have no power, food, air, etc. The tube that is under construction does not act as a connection while it is under construction. This leads to rapid death...
Those are the main problems I've encountered (among other lesser ones). It's a long post so I don't expect anyone to read it all. Please refrain from "Please summarize for me" because this already is a summary! :lol: :lol: :lol: