He or Trevor can be killed in GTA V, or they can both live.
Michael was a football star in high school.
Michael's determinant death had been foreshadowed in past missions in GTA V.
After Michael manages to reunite his family in "Reuniting the Family", Amanda will send Michael a text message, where she says "I want to bury you, when the time comes, as your wife.". This is in reference to "The Time's Come", the optional final mission where Michael's demise happens.
After "The Wrap Up", during the cutscene where Michael and Trevor regroup after what happened at Kortz Center, Trevor will say that they need to pull one last score (referring to "The Big One"), afterwards he says that if Michael can make it happen, he says "So that means, I won't have to put a little bullet in your head". Ironically, when Franklin decides to call Trevor to help him take Michael out in "The Time's Come", he won't help him, stating that "he has had enough traitors in his life".