Out of all the people you'd think O-dawg...

O-Dog is basically a cockroach. He'll survive the apocalypse

In all honesty though it was played out to invoke emotions from the audience. O-Dog deserved to die after all the murders he's committed, with no remorse shown at all. He's literally a psychopath. The others, who wanted to do well for themselves, had to go, because there really is no escaping the hood. Stacy (the football player) is probably next to die, word to Boyz n The Hood