So last night I found my base was falling apart beyond my ability to bring it back for reasons I don't completely understand. My technicians weren't repairing anything so oxygen generates were almost all gone, fires were constantly happening because technicians weren't maintaing the fire extinguishers either.
With last 3 people running around unable to really keep fires out, I was boarded by 3 raiders who easily took out these last 3 people. I found my base now had lost all inhabitants except for 3 raiders roaming the base looking for people to shoot (I guess). Clearly they were not starting to maintain things or putting out fires. Yet the game kept on going with no functioning oxygen generators, no one to put out the fires, but 3 raiders roaming around the halls. I seemed to still get new messages about passing ships, but that seemed kind of pointless.
I know it's an alpha, but I think I had a expectation that my base would destruct and take the raiders with it. Seems like that might be a good sort of bottom condition -- a point at which your base completely looses its lifesupport/integrity and blows up.