Long Island College Hospital is in the process of clearing the Brooklyn facility of its patients.
The cash-strapped, 250-bed facility in Cobble Hill is part of SUNY Downstate, a Brooklyn hospital network and teaching center.
The nurses union says its members at LICH have been instructed to prepare patients for transfer to other facilities and assist in the rescheduling of future appointments and procedures at other facilities in Brooklyn.
Despite a restraining order from a state judge, Downstate has barred ambulances from LICH's emergency room, halted new admissions and closed some departments.
SUNY called claims that it is attempting to close the hospital "false statements and rumors" — and said that it is not in violation of any court order.