L-374 III

From Memory Alpha, the free Star Trek reference

The M-class world L-374 III was the third planet in the L-374 system.

In 2267, the entire crew of the Federation starship USS Constellation, consisting of 400 men and women, was beamed down to this planet for safety against the doomsday machine which was attacking the Constellation with her Captain, Commodore Matt Decker still aboard the starship trying to outrun the machine. When the Constellation was disabled, the Doomsday machine turned onto L-374 III. Severely damaged and with transporters offline, there was nothing Decker could do to save his helpless crew.

As a result, the doomsday machine destroyed the third planet and blasted it to rubble and debris, and Decker's entire crew was killed. (TOS: "The Doomsday Machine")