Zach Sobiech was a teenager diagnosed with steosarcoma, a rare form of bone cancer. Given only months to live, Zach decided to write a song to say goodbye called 'Clouds.' His message was soon heard across the country and a number of celebrities teamed up to help him spread the word; not because he was dying, but because of how he lived.

Zach passed away in May but his memory lives on. You can download 'Clouds' on iTunes and support Zach's Osteosarcoma fund. Proceeds benefit the Zach Sobiech Research Fund of Children's Cancer Research Fund.

Watch Zach's touching story as he records his last days on earth.  Grab a tissue or two, you're going to need them.