Bases aren't destructable. Had a Bethke happen in a Hostile Patrol Mission.
I had an NCA and 2 NCDRs. Three AI Allied Kzinti, no Idea what they were. vs a C8KR, D5KR, D7ER, and another D5 type. I think it was a C. And a Klingon BSF. When the D5KR was destroyed, my NCA went with it. The two remaining NCDRs and a Kzinti MAC destroyed the Base, but it was still there after the mission.