Sage Michael Warren, the 21-year-old son of songwriter Brad Warren and his wife Michelle, has died. The family made the announcement on Thursday. His cause of death has not been released. Brad and his brother Brett, who are known as the Warren Brothers, have been hit songwriters in Nashville since the 90's. They are behind Toby Keith's "Red Solo Cup", Blake Shelton's "Every Time I Hear That Song" and Jason Aldean's "We Back".