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(TMZ) - Several stage hands were rushed to the hospital Thursday night after Luke Bryan's Ohio State concert ... after the singer's stage collapsed, TMZ has learned.

Law enforcement sources tell TMZ ... a forklift crashed into a portion of the stage during take down, and it crumpled.

TMZ reports 4 people -- including guys from Luke's crew as well as arena staff -- were taken to a nearby hospital with injuries.  Their current medical status is unclear.

Luke's next concert -- scheduled for tonight in Lexington, KY -- has been pushed to February because of obvious stage problems.