From Halopedia, the Halo wiki
Carter Guard Armory was an armory of the United Nations Space Command. In early January 2550, the armory was raided by the Banished, led by Atriox. The Banished killed Carter Guard Armory's entire garrison and stole all of its equipment. Footage—recorded by Sergeant B. Wright—of the slaughter of Orbital Drop Shock Troopers stationed there offered the Office of Naval Intelligence its first introduction to Atriox and the Banished.