Praxis

The Klingons demonstrate how not to operate a lunar power-generating facility.

Praxis was a moon of the Klingon homeworld, Qo'noS. In the late 23rd century, a power-generating facility on Praxis exploded, destroying the moon, severely damaging the atmosphere of Quo'nos, and sending a subspace shockwave through space that could rock starships light-years away.