The family of 19-year-old Crystal Montgomery announced her death on Facebook.Story continues below
He quietly visited Montgomery at Edmonton's Cross Cancer Clinic before heading to his sold-out concert at Rexall Place.
He then tweeted a photo of them both smiling from her hospital room.
Montgomery's mother, Rita, says on Facebook that her beautiful girl is now free of pain.
"We will forever love her and never forget her," she said Thursday. "Crystal, you are going to be the most happiest angel."
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