When Zach Sobiech was told that he only had months to live, his response was to “embrace every day with hope and joy,” and as described in the text of the “Clouds” video, he turned to music to say goodbye.

Released in December, the video went viral, and tugged at the heartstrings of viewers around the world, and eventually led to a celebrity tribute video featuring Bryan Cranston, Anna Faris, Sarah Silverman, Ed Helms, Jenna Elfman, Jason Mraz and others.

Sobiech was diagnosed with osterosarcoma (a rare, cancerous bone tumor that develops in children) in November 2009. He went through several surgeries and months of chemotherapy. At the end of last May, cancer was found in his pelvis and lungs. “There are no effective treatments left,” the video says.

Zach’s mother Laura posted the following message to website CaringBridge.org today:

Zachary passed away this morning. He was surrounded by his sisters, brother, parents and girlfriend. We love him dearly.

A concert is scheduled for this coming Saturday to raise money for Sobiech’s fund, which aims to raise money to fight the disease. Donations are also being accepted here.

Clouds is currently approaching 3 million views on YouTube.

Here’s another song Zach and his group A Firm Handshake released in February:

[via Today]