MURRELLS INLET, S.C. – An off-duty Connecticut police sergeant died Sunday after he was reportedly assaulted in a popular South Carolina bar.

Sgt. Matthew Mainieri, 41, a decorated 20-year member of the South Windsor Police Department, died Sunday afternoon after he tried to break up a fight at Uncle Tito’s in Murrells Inlet, Fox 61 Connecticut reported.

Connecticut Police Sergeant

Sgt. Matthew Mainieri of the South Windsor Police Department in Connecticut. (South Windsor Police Department)

Mainieri suffered head injuries during the altercation and was pronounced dead Sunday afternoon, the station reported.

“It is with profound sadness that the members of the South Windsor Police Department mourn the death of Sergeant Matthew Mainieri,” South Windsor Deputy Police Chief Scott Custer said.

Mainieri was trying to break up a fight when he suffered a fatal head blow, Custer said.

“That’s who Matt was,’’ Custer wrote in an email, “someone who always helped those who needed help, anytime and any way he could.”

Deputies with the Georgetown County Sheriff’s Office booked Kelton Jess Todd, 21, of Aynor, S.C., in jail for assaulting Mainieri.

However, as a result of Mainieri’s death, more serious charges are pending, the sheriff’s office said.

Connecticut police sergeant

Booking photo of Kelton Jess Todd, 21, of Aynor, South Carolina. (Georgetown County Sheriff’s Office)

The off-duty sergeant was vacationing with friends at the time. Uncle Tito’s is near Myrtle Beach.

His police work earned Mainieri commendations, including the Medal of Valor, according to Custer.

Mainieri began his career in law enforcement in January of 1998, when he was hired as a community service officer. He became a police officer the following year.

As he rose through the ranks from officer to sergeant, Mainieri served in the traffic and detective divisions. He was member of the regional traffic unit and was an accident reconstruction expert.

Mainieri also served on the regional emergency services team and was skilled at explosive breaching, Custer said.

In July of 2009, Mainieri and two other South Windsor officers received special recognition for their response to a 13-hour hostage standoff at a house, the Hartford Courant reported.

The standoff ended with Mainieri and Sgt. Peter Alix taking suspect, Richard Shenkman, into custody, according to the paper. Shenkman had kidnapped his ex-wife and set fire to the house. Consequently, he is currently serving a 70-year prison sentence.

In recent months, Mainieri was key in helping the department launch a drone program.

Off-duty, he spent his time riding motorcycles, often traveling to Vermont and South Carolina with friends.

He leaves behind his mother, sister, girlfriend and countless friends.