Tragically Hip frontman Gord Downie put on a surprise performance at a We Day youth empowerment event in Halifax on Wednesday.

Downie, who is battling brain cancer, was a last minute edition to the event, which also included Margaret Trudeau, Rick Hansen and Classified.

Downie performed a song from his solo project Secret Path, which tells the true story of 12-year-old Chanie Wenjack, who died after running away from a residential school in northern Ontario 50 years ago.

"On Oct. 16, 1966, Chanie escaped and followed a secret path through the woods,” We Day staff head Talitha Tolles told the crowd of over 8,000 students. “Trying to walk home, he struggled through snow squalls and freezing rain. He never made it home, dying of exposure."

Downie’s brother Mark Downie was also on hand to share Chanie’s story, putting a spotlight on the 150,000 children taken from their families and sent to residential schools.

“They were literally raised by strangers for long stretches without the most important gift every child requires – that's love," Mark Downie told the crowd. "We really want your help, all 8,000 of you. Will you help the Gord Downie Chanie Wenjack Fund?”

After his performance, Gord Downie was joined on stage by Wenjack’s sisters, Daisy and Pearl, for a prayer with a powerful message.

“This is a prayer for all people… black, white, yellow and red,” said Pearl Wenjack. “Remember all the people who go through life and trials and tribulations. They need our prayer.”

Downie performed his Secret Path show the night before to a sold-out audience at Halifax's Rebecca Cohn theatre.

We Day describes itself as "a movement that brings people together and gives them the tools to change the world," while celebrating youth efforts on issues such as homelessness and poverty.

With files from CTV Atlantic’s Amanda Debison and The Canadian Press.