When Zach Sobiech was diagnosed with terminal cancer, he decided to make music to chronicle his journey.

The 18-year-old’s song “Clouds” went viral on YouTube with close to 3 million views. On Monday, Sobiech’s family announced that their son had died from the disease, CNN reports.

“Our family has been blessed, not only by his amazing presence in our lives, but also by the love and support of our family and friends and by so many people in the community. In particular, we’d like to thank those people who listened with their hearts and helped Zach bring his message and his music to the world,” Sobiech’s family said in a statement.

The high school senior used his music to raise money for the Zach Sobiech Osteosarcoma Fund, the Stillwater Gazette reports. His CD sales raised nearly $100,000 with $10,000 more expected from download sales and royalties, the Minneapolis Star Tribune reports.

"I'm not good at writing letters," Sobiech told the Pioneer Press in December. "So I figured instead I could just write songs for people, and they might be around longer. It's more powerful than writing a letter, because a song can get stuck in your head. You find yourself humming it during the day."

Sobiech’s Internet fame reached Hollywood. Jason Mraz, Anna Faris and Rainn Wilson are among the celebrities that took turns lip-synching to “Clouds.”

On May 3, Sobiech’s eighteenth birthday, Justin Baldoni published a documentary about the teen battling osteosarcoma called “My Last Days.”

"Going out to see Zach in Minnesota was one of the greatest experiences of my life," Baldoni told CNN. "He is this old soul who inspires everyone he meets. You leave and you think: 'I want to be a better person.'"

In 2009, Sobiech was diagnosed with osteosarcoma. He was hospitalized for a month and had 10 surgeries and 20 rounds of chemotherapy, CBS Minnesota reports.

Sobiech’s “Clouds” was meant as a farewell to his family and friends.

“Maybe someday I’ll see you again,” he sang. “We’ll fly up in the clouds, and we’ll never see the end.”