O'Brien (Reach)
From Halopedia, the Halo wiki
Template:Human Character Infobox Private O'Brien was one of the UNSC Marines aboard Reach Station Gamma, Dock 9, above Reach.
Biography
Battle of Reach
He, along with SSgt Avery Johnson, PFC Wallace A. Jenkins, and Private Bisenti, were there 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.
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 did 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.
Speculation
It is likely he was the Crazed Marine from 343 Guilty Spark, as in The Fall of Reach, when John encounters Johnson's squad, Jenkins and Bisenti are also part of it. The Crazed Marine only mentions Johnson, Bisenti, and Jenkins, and not Mendoza, however Mendoza's body is found later.
