Earth Alliance President Luis Santiago, a strong proponent of interstellar diplomacy and supporter of the Babylon Project, chooses to visit the Babylon 5 station in 2258. He travels to the station on board EarthForce One, accompanied by an escort of Starfury fighters bearing the Presidential livery. During the visit, he delivers a public address on the station and presents a wing of Starfuries to complete the station's fighter complement; the wing is designated Zeta wing. In common with many Babylon 5 characters, the image/voice of Santiago was actually one of the shows producers, Douglas Netter.
Shortly after midnight on January 1, 2259, EarthForce One explodes, killing President Santiago. The transport is in the vicinity of the transfer point at Io at the time of its destruction. Prior to his assassination, President Santiago had been due to deliver his New Year's address. This would have been a turning point in Earth policy towards aliens in a positive direction - Clark and his forces could not permit it to be delivered. Santiago's Vice-President, William Morgan Clark, assumes the presidency after being sworn in aboard EarthForce Two, the official transport of the Earth Alliance Vice-President. Suspiciously, Vice-President Clark had disembarked EarthForce One shortly before the explosion, complaining of a viral infection.
Clark is later implicated in the assassination plot and his government is overthrown during a revolt led by Captain John Sheridan three years later.