The Installation 00 incident, also known as the Ark incident and officially referred to as the TOUCAN BLUE event, was a highly classified event occurring during Operation: KEY HOLE on April 14 and 15 2553, in orbit of the heavily damaged Installation 00. The incident led to the first contact between the Ve'nek, Theran, Human and Sangheili species, and began a sequence of events which would later lead to the end of the Remnant War and the establishment of the Unified Coalition of Governments.