Mirror universe
(coexisting on another dimensional plane)
(coexisting on another dimensional plane)
Inhabitants of Vega IX.
Executed colonists
These five thousand colonists were executed by the mirror universe's Captain James T. Kirk, his second action after assuming command of the ISS Enterprise from the assasinated Christopher Pike.
While stuck in the mirror universe briefly in 2267, the prime universe's James T. Kirk asked the ship's computer to read the official record of the starship's current command, and learned of the colonists' deaths. (TOS: "Mirror, Mirror")
These colonists were only mentioned in dialogue.