NEW YORK (WCBS 880) – Officers are still in shock after a Long Island police officer was struck and killed on the Long Island Expressway on Friday night.

Officer Michael Califano pulled over on the Expressway around 11 p.m. to do a vehicle and traffic stop when a truck struck his car from behind, crushing his car.

He died on Saturday morning and now his fellow officers are mourning for his loss.

“He’s the father of three—three boys—married to a loving wife, lives in Nassau County, works in Nassau County, played in Nassau County and now unfortunately, we’ve lost one of our best,” Lt. Kevin Smith said.

 LISTEN: WCBS 880’s Sophia Hall reports

Califano lived in Wantagh, Long Island with his wife Jacqueline and his three boys—ages 6 to 13 years old. Califano began his career with the Nassau County police department in 1998 he was 44 years old.

Smith said over the years the department received many letters about the kind things Califano did—including recently.

“It was from an elderly woman who was stopped on the side of the road and whose muffler was hanging down from her car. And instead of calling a two truck–he actually crawled under her car and was able to fasten the exhaust muffler back up so she could get home,” Smith said.

To honor and remember Califano, flags are flying at half staff across the county.

Authorities have charged the driver with criminally negligent homicide for allegedly falling asleep behind the wheel.

READ MORE: Police Officer Dies In LIE Crash; Man Charged With Homicide

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