An Irish-born New Jersey cop died in a tragic collision while on duty Monday night.

State Trooper Sean E. Cullen, 31, was among a group of police officers and firefighters at the scene of a car fire along I-295 near West Deptford in Gloucester County.

As he helped attend to the scene, he was struck by a passing vehicle, which also hit the car that was on fire.

Trooper Cullen sustained severe head injuries and was rushed via helicopter to Cooper University Hospital. He was pronounced dead four and a half hours later. He leaves behind a fiancée and their nine-month-old baby, his parents, a sister and two brothers, who of whom, Garrett, is a New Jersey State Police Detective.

Cullen was born in Dublin in 1985 and emigrated to the US with his family three years later. According to a Facebook post from the New Jersey State Police, he was a 2003 graduate of Cinnaminson High School and an All-American wrestler at Lycoming College in Pennsylvania, where he earned a Bachelor of Arts degree in Criminal Justice in 2007.

Today, we extend our deepest condolences to the family and friends of Trooper Sean E. Cullen #7594, who was tragically...

Posted by New Jersey State Police on Tuesday, March 8, 2016

He began his law enforcement career as a Class II Police Officer in the Sea Isle City and Mount Holly Police Departments and served as a Patrolman for the Westampton Police Department. With a lifelong dream of being a cop, he enlisted in the New Jersey State Police on August 29, 2014, as a member of the 154th Recruit Class. He was assigned to Troop "A,” serving at Buena Vista and Bellmawr Stations.

"The sudden and tragic loss of New Jersey State Trooper Sean Cullen reminds us how fragile life truly is and the dangers police officers face daily on the job," Governor Chris Christie said in a statement.

"He legitimately was a great guy and I'm going to tell you, there's probably not a single person who would say a negative thing about him," Sgt. Victor Bialous of the Westhampton Township Police told ABC 6 News.

Troopers salute as flag raised, then lowered to half staff in Bellmawr, where fallen Trooper Cullen was stationed.

— Katherine Scott (@KScott6abc) March 8, 2016

“Becoming full time here in Westampton was everything to him, but I think when he had the opportunity to work side-by-side with his brother and be a state trooper, that was his goal," Bialous said, adding that “family means everything to him. He comes from a nice, tight-knit family.”

In an emotional Facebook post, one of Cullen’s friends, Sean Einstein, described him as “the Jim Carey of our small community of those in Public Service. No matter how angry, frustrated, sad, tired or stressed we were, you came up with some stupid comment to make us laugh.”

Friends and family also spoke with NBC10 news, offering tributes to Cullen.

A celebration of his life will be held Sunday afternoon from 2 p.m. to 7 p.m. and Monday morning from 8 a.m. to 11:30 a.m. at Saint Borromeo Church in Cinnaminson. A funeral service will follow.

The 22-year-old woman who was driving the car that struck Cullen has cooperated with police and is not believed to have been under the influence of alcohol or drugs at the time of the crash, NBC 10 reported. No charges have been filed.