There's a part in Dexter where his wife gets murdered and left in a tub full of blood and Dex is left to raise their baby (who was also sitting in a puddle of his mother's blood on the bathroom floor) without her.
Barry Miller's character, Bobby C had a tragic death in Saturday Night Fever. He tries to get advice from everyone for his girlfriend to get an abortion but it fails. He gets depression and fools around on the Verrazano-Narrows bridge and end up dying from that fall. :(