Its great you brought this up, cause that is bassically how I lost my 33 dwellers to only having 7, one radroach would not die and kept killing my people, then as if hte game wanted to rub it in my face I get on the next day and the bodies disappearred on there own.
So, anyone still having problems with runaway radroaches? I've never had that problem myself, but just toying around with a new vault, I present the perfect solution:
Don't build rooms next to each other. Build them like this:
Entrance - Living Quarters
Powerplant - EMPTY
EMPTY - Cafeteria
Water - EMPTY
See what I did there?
No matter which room the radroaches surface in, they'll never spread.
Sure, it costs a bit more in elevators, but they are cheap as hell.
When you get enough weapons and trained dwellers, you can fill up the spaces at your own pace.
(I have confirmed that this works.)
I just lost 34 of my 37 fully equipped dwellers to a devestating radroach invasion. I tried my best to bring them back but after two days I only had 20 dwellers and the rest disappeared. 14 souls lost to a game breaking bug. Now I've been breeding like mad to replace them but I'm terrified to open the app for more than 10 seconds at a time in case the super radroaches return.