UPDATE: A man surrendered the following Thursday to face involuntary manslaughter charges.

A man died from his injuries after he was punched by another man during an argument at a South Philadelphia dog park Saturday night.

Drew Justice, 38, and his fiancée were walking their dog at the Gold Star Park along the 600 block of Wharton Street around 9:15 p.m. While at the park, Justice began arguing with another man after telling him to put his dog on a leash, witnesses said.

"He was scared," Anthony Barosso of South Philadelphia said. "It was a pit bull opposed to two little puppies."

The argument escalated and the unidentified man punched Justice, causing him to fall backwards and hit his head on the ground. The suspect then fled the scene. Police responded to the dog park after receiving a report of a person screaming.

"I heard the screaming," Justice's neighbor Julie Abruzzese told NBC10. "But it was already done. He was laying on the ground."

Justice was taken to Jefferson Hospital where he was pronounced dead at 9:51 p.m.

Witnesses told NBC10 they don’t believe the attacker meant to kill Justice but that he still ran away after punching him. They also said several people tried to resuscitate Justice though they believe he died instantly.

"Him and his fiancée were ready to get married," Abruzzese said. "It's heartbreaking."

Investigators interviewed a person of interest in the incident though no arrests have been made. They are also interviewing witnesses.

Police described the suspect as an “unknown white male wearing dark clothing,” but have not released a more detailed description beyond that.

"They got some surveillance, I know that," Anthony Barosso of South Philadelphia, said. "But they don't have a good picture because there's no lighting here."

Residents told NBC10 there's been recent tension at the popular park due to a mix of dogs and children.

"They're going to tell you their dog's friendly," Abruzzese said. "You don't know at that moment if a dog's going to turn. I've always said that one day they're going to bite these children. But here it turned out somebody got killed over a leash."

If you have any information on the incident, please call Philadelphia police at 215-686-TIPS.