The Zenitaf Calamity was a Gray Goo Event that led to the complete destruction of the planet Zenitaf and the extinction of the Yurigans, as well as the creation of Memento.
The event was caused during a demonstration of Amplicorp’s upcoming Polyfold Nanites being showcased by Isaac Grant. Where the nanites suddenly began to deconstruct all nearby matter. Several attempts were made to contain the swarm with Hardlight and EMP tech. But the nanites were extremely resilient and persistent, eventually overtaking the planet regardless. A few wealthy individuals attempted to escape the planet through spaceships, but most were taken down by the swarm or failed to safely exit atmosphere in the rush.