The Earth Crisis is a major event in the Mega Man X timeline. This incident takes place in Mega Man X5.
History[]
In the late 21XX period, some months following the Great Repliforce War, the Maverick Sigma had concocted a plan to awaken the "true self" of the Maverick Hunter Zero. Assisted by an unseen, unnamed accomplice, Sigma planned to restore Zero to his original violent state by scattering the Sigma Virus across the Earth and by infecting the Space Colony Eurasia with a similar virus and crash the colony into Earth. By combining the Colony virus and his own virus and infecting Zero with the new strain, Sigma hoped to use Zero to destroy Mega Man X.
Sigma hired the Reploid mercenary Dynamo to sabotage the Eurasia Colony and infect its main computer with a virus. While Dynamo carried out this task, Sigma started a Maverick outbreak to gain the attention of the Maverick Hunters. When X and Zero inevitably confronted him, Sigma lost on purpose. As his physical form was destroyed, Sigma's viral essence was scattered far and wide, quickly spreading across the planet and causing Reploids all over the world to turn Maverick.
The Maverick Hunters worked frantically to suppress the worldwide violence and gather materials that they would need to prevent Eurasia from colliding with the Earth. They rebuilt an ageing energy weapon called the Enigma Cannon and fired it at Eurasia, but the blast was not enough to completely vaporise the colony and a large portion struck the planet, causing widespread ecological damage. With the ecosystem destroyed, humanity was forced to take shelter underground, leaving Reploids responsible for rebuilding the surface world. It would not be until the early 22XX period that the planet's surface could support human life again.