LINDEN - An off-duty Linden police officer is one of two people killed in a wrong-way crash on Staten Island early Friday morning.

The New York Police Department says a tractor-trailer was heading southbound on the West Shore Expressway (Route 440) near Arthur Kill Road when it collided head-on with a vehicle carrying four people just before 5 a.m.

Officer Frank Viggiano, 28, and his friend, 27-year-old Joe Rodriguez, of Linden, were killed in the crash. Officer Viggiano was a five-year veteran of the Linden Police Department.

Officer Patrick Kudlac, 23, and Officer Pedro Abad, 27, suffered severe injuries in the incident. Both have undergone surgery at hospitals in Staten Island. They both remained in critical but stable condition Saturday.

The officers were all off duty at the time.

"This is obviously a sad day for the Linden families and for our Linden Police Department," says Linden Mayor Derek Armstead. "My heart and prayers go out to the families that are affected."

Authorities say they have applied for a warrant to test the blood-alcohol level of Officer Abad, who was driving. His blood has since been drawn.

The truck driver was treated at a hospital for injuries that were not considered life-threatening.