An off-duty NYPD officer was seriously injured early Sunday morning after a car crashed into him and another car on the shoulder of the Long Island Expressway, police said.

It happened around 12:30 a.m. Sunday near Exit 53, around Brentwood.

Suffolk County police said off-duty NYPD Officer Anthony Robitaille and another driver had both pulled over and exited of their cars on the highway shoulder. It is not confirmed why they had stopped.

A Ford sedan, driven by 33-year-old Desirea Coyle, then hit the rear of Robitaille's car, propelling it into him and the other stopped car, Suffolk County police said.

The 27-year-old Robitaille, who works in the 75th Precinct in Brooklyn, was flown to a hospital with serious injuries.

Officials said Coyle was taken to a local hospital with minor injuries, and the other driver was not hurt.

All three cars are undergoing safety checks as police investigate.

Map image above courtesy of Google.