The normally bright, humming atmosphere of Rittenhouse Square had a dark cloud over it Monday as the city mourned the death of one of its suburban neighbors.

A young man out celebrating St. Patrick’s Day with friends fell victim to a senseless slaying at the posh Philadelphia square in the early morning hours Sunday when a homeless man stabbed him in the chest for no apparent reason, according to police.

Forty-year old Steven Simminger, from Media, has been charged with the murder of 24-year old Colin McGovern, of Churchville, Bucks County. Police brought the charges Monday afternoon.

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It was just after 3 a.m. Sunday when police said officers responded to a radio call for a fight along the 1800 block of West Rittenhouse Square. Upon their arrival, officers reportedly observed McGovern bleeding from multiple stab wounds to the torso. He was rushed to Hahnemann Hospital, where he was pronounced dead at 3:36 a.m.

An early investigation revealed that McGovern and his friends were involved in a verbal altercation with Simminger over the Simminger wearing a New Jersey Devils baseball cap. The fight reportedly escalated quickly and resulted in Simminger pulling a knife.

Nicole Bell is the general manager of Dandelion, a restaurant on Rittenhouse Square at Sansom Street. She told Metro that only two weeks ago, she was walking home from work one night along the 1900 block of Sansom Street around 8:30 p.m. when she encountered an unknown male 10 to 15 feet away from her walking towards her on the sidewalk.

She said that just as she was about to pass him, she looked up and saw him take his hand out of his pocket. That’s when he punched her smack in the face, Bell said.

Bell said this attack was unprovoked and her assailant did not look homeless, but he fled in an unknown direction and she fell into the street. A good Samaritan came over to her aid and helped her call 911.

“I walk passed people all the time and now I flinch, because I never saw this coming,” said Bell.

“There were no warming signs that he was going to do that. Everybody I look at now...I don’t walk down Sansom Street anymore and I walk directly home. I’ll even take a cab home and I only live two and a half blocks away from work.” 

RELATED: Man dies after apparent random stabbing in Rittenhouse Square

Carol Serena, another general manager of a restaurant on Rittenhouse Square, Parc, said that there has been a lot of speculation from residents who live on the square about what happened early Sunday morning.

“It was Erin express. There was a tremendous amount of drinking going on in the city. Hey, I’m a New Yorker and I’m all about it. I love St. Paddy’s Day better than anyone,” she said.

“This young kid, he didn’t do anything wrong. Whoever this person was, I’m sure he wasn’t affiliated with anyone around Rittenhouse. It’s a very sad thing that happened. A lot of people think Rittenhouse should be devoid of anything terrible, but this type of thing shouldn’t happen anywhere.”