If this doesn't tug on your heart strings, nothing will.

Check out this viral video, in which a woman records her 93-year-old grandfather singing to his dying wife in her hospital bed. And it's not just any song, either. He sings "You’ll Never Know," by Rosemary Clooney with Harry James, which has special meaning to the couple. As the video description explains:

Howard (Grandpa) is singing to her their love song, the song that comforted her when he went away to fight in World War II. At family gatherings, it was not uncommon for the two of them to sing this song together, each taking a verse and serenading the other. In fact, after fifty years of marriage, they renewed their vows and performed this song as a duet for the entire family at the reception.

The grandmother, Laura, can only see shadows and can't sing, but she does her best to speak some of the lyrics along with Howard, who had to be propped up out of his wheelchair and held by a therapist during the moving performance.

Yeah, this clip has emotions coming from all angles.

At the time the video was posted, the grandmother was still alive.