Destruction of Praxis

The Destruction of Praxis, also known as the Praxis disaster, took place in 2293 when the klingons over-mined and had insufficient safety precautions.

Prelude
For centuries, Praxis served as the key-energy production for both the Klingon Empire and Qo'noS for pergium, topaline and uranium. During the Federation-Klingon Cold War, the klingons put a great strain on the energy production during their 70 years of conflict with the Federation.

Destruction
As the klingons continued to mine Praxis, the moon became unstable and its core became unstable.

In 2293, one of Praxis's quantum reactors overloaded. Praxis exploded and created a shockwave that went beyond the Neutral Zone. The USS Excelsior (NCC-2000) under Captain Hikaru Sulu was hit by the shock wave. The Excelsior 's science officer, Dmitri Valtane confirmed that the shock wave had come from Praxis. The Excelsior 's communications officer, Janice Rand, then picked up a distress signal from Kenk. However, Brigadier Kerla, military adviser to the Klingon Council's Chancellor Gorkon, sent a message saying there was a accident on Praxis and the Excelsior to stay out of the neutral zone.

In truth, the explosion had crippled the Empire's energy resources, Qo'noS ozone had been damaged, and it's oxygen would be depleted within 50 earth years.

Aftermath
Three months later, the USS Enterprise (NCC-1701-A) first officer, Captain Spock opened a dialogue between himself and Gorkon at the behest of his father, Ambassador Sarek. These negotiations would eventually lead to the dismantlement of the Neutral zone between the Klingons and FederationHowever, certain members of Klingons, Romulans, and even Starfleet conspired to put an end to these negotiations.