O'Brien (Reach)

Private O'Brien was one of the UNSC Marines aboard Reach Station Gamma, Dock 9, above Reach.

Biography

Main article: Battle of Reach

O'Brien, along with Staff Sergeant Avery Johnson, PFC Wallace A. Jenkins, and Private Bisenti, were fighting a group of Kig-yar when MCPO John-117 and PO2 Linda-058 boarded the station to destroy the logs of the ONI ship, UNSC Circumference.

Main article: Battle of Installation 04

"Glad you could make it, Chief... we saved some party favors just for you."

— O'Brien greets John-117 on board the Pillar of Autumn

He was picked up with Johnson and the Chief when they took a Pelican and flew back to the UNSC Pillar of Autumn. When the Pillar of Autumn was boarded, John-117 recognized him (but could not remember his name) and saved him from a Kig-yar soldier. He was killed either when the Covenant boarded the Pillar of Autumn or during the Battle of Installation 04.