Legends of the Fall

Susannah (Julia Ormond) marries Alfred (Aidan Quinn), but they never have children. Tristan and Isabel Two (Brad Pitt, Karina Lombard) get married and have two children. Isabel Two is killed by a bullet meant for Tristan that ricochets. Susannah kills herself. Tristan (surprisingly) lives to a ripe old age and is killed in a fight with a bear.
Thanks, Kira M!