James Edmund Caan was an athletic kid from the Bronx, the son of German-Jewish.
He died on July 6, according to a post on his official Twitter account.
After starting in theater and television, Caan burst into Hollywood like a comet, appearing in films by some of the most renowned auteurs of the era.
Best known for his explosive turn as Sonny Corleone in The Godfather and as a dying professional football player in the made-for-TV-movie Brian's Song (which earned him Oscar and Emmy nominations, respectively)
Caan married and divorced several times, got into on-set arguments and publicly struggled with substance abuse and depression.
In Gardens of Stone, he was a heartsick Vietnam vet reluctantly guarding the Tomb of the Unknown Soldier.
In Elf, he played against type as a failing children's book publisher who is also the main character's dad.