BREAKING NEWS - David Copperfield's Magic Turns Bloody

An X17 photog told us earlier today about an accident during magician David Copperfield's Vegas MGM Grand stage show that left the magic man's assistant in the hospital after a bloody stage accident. We're trying to track down some video of the incident ...

Now Us Weekly is reporting details of the accident ... one of Copperfield's stage assistants was drawn into a 12-foot high industrial fan used during one of the tricks, and the moving blades caused injuries to his arm and face.

When the paramedics were able to free the man from the fan, he had suffered severe bleeding and multiple fractures in his arm. A fire department spokesman told Us, "The surgery was several hours wherein the doctors could insert pins and bolts," the rep says. "There was a puncture on his face requiring eight or nine stitches. The Copperfield crew waited at the hospital during his arm and face surgery."

David himself was in the assistant's hospital room when he woke from the surgery, and gave him a child's magic trick set with which to "practice" while he recovers.

Hotel sources tell Us Weekly the show will go on tomorrow ...