Manuel Mendoza

Private Manuel Mendoza was one of the Marines who survived the crash landing on Installation 04. He was the Marine that Sergant Avery Johnson loved to yell at. He was part of Fireteam Charlie, who were led by Captain Keyes to find the "weapon cache" that 'Qualomee had told them about. Instead, the so-called "cache" turned out to be the main holding area for the Flood, and all of their team, save for Sergeant Johnson were attacked and assimilated by the Flood, and turned into Flood Combat Forms. Mendoza attempted to escape the room, but the infection forms were able to infect him before he reached the door. Mendoza finally died when SPARTAN-117 shot the infected marine with a Shotgun and ended his suffering. The Master Chief notices that the infection form had taken up residence inside the soldier's chest cavity, and seemed to have extended their tentacles into certain parts of the body. .

Trivia
There is also a glitch in Halo: Combat Evolved that allows you to get back on board the Pelican in the level 343 Guilty Spark. Once the Pelican lands, the player may run around the perimeter of the level, where Private Mendoza stands, surrounded by many dead combat floods in the area. Also by doing this, the player can skip most of the outdoor portion of the level. To do this, throw a grenade as the Pelican is landing and you will stay inside the ship. It will then crash some way away and you can explore the upper area of the level.