He wrote the song, "Clouds," as a farewell. Hallberg said proceeds from the sale of the song, and Sobiech's other music, are going to the Zach Sobiech Osteosarcoma Fund, which Zach wanted set up so that more research could be done to find better ways to treat this form of childhood cancer.
"That will be Zach's lasting legacy," Hallberg said.
Zach's family members were declining interviews but said in a statement that they felt blessed by Zach's "amazing presence" in their lives. They thanked those who "listened with their hearts and helped Zach bring his message and his music to the world."
Zach Sobiech's "Clouds" video: http://bit.ly/UIGq9r