According to accounts, it happened about 20 minutes into his performance.
Carlos Santana just “passed out” on stage.
“Members of the medical community may now join the audience.” The crowd demanded that he be treated since he had a “severe medical concern.”
According to concertgoers interviewed by The Detroit News, Santana was in the middle of performing “Joy” when the music was abruptly shut off.

He eventually passed out after a while of aimless walking and playing.