A certified nurse’s assistant claims in a lawsuit that she was flattened by a man who fell into an atrium two floors below at Wyckoff Heights Medical Center.

Marie Daphnee St. Sume was with a patient Dec. 11 when “bodies started flying — and it wasn’t ‘Mary Poppins,’ ” said her lawyer, David Jaroslawicz, after filing suit in Brooklyn Supreme Court.

St. Sume, 29, suffered a concussion, headaches and neck pain, the lawsuit says.

The hospital did not respond to a request for comment.