An off-duty NYPD officer was killed in a crash on the Long Island Expressway Monday night, police say.

The crash happened just before 11 p.m. Monday on the eastbound side of the expressway in Brentwood, just west of Exit 53.

Police say 30-year-old Ryan McKenna, of Hicksville, was driving a Nissan Frontier on the LIE when the vehicle struck the median and flip in the HOV lane.

The NYPD confirmed McKenna is an off-duty officer from its department.