Of all the deaths in Halo, this was the one hardest for me to accept, and here is why…
Everyone else, who we are shown to have died while serving as part of team noble, saw it coming. Each one of them knew their time was almost up and walked straight to the end. Kat was never given this dignity.
During the Fall of Reach, Jorge willingly stayed behind to detonate a weapon manually to try and defeat the enemy; Carter intentionally flew a Pelican into enemy forces to give the remaining two members a chance to complete their mission; Emile died giving cover to friendly forces so Noble Six could escape with Cortana against insurmountable odds (last words, “I’m ready. How ‘bout you?”); and Noble Six chose to stay behind and die alone after taking Emile’s place and making sure the ship carrying Cortana escaped.
Kat’s chance was taken away from her before the Fall of Reach, back in the Battle of Fumirole, where she was incapacitated while trying to deliver a nuclear device to an enemy ship. Thom, one of her team members at the time, died in Kat’s place when she was no longer able to complete her mission.
Kat would have done the same as any of her team mates had their roles been reversed, instead she ended up being put down by a random (not too random) sniper during the Fall of Reach.