The gym at 25th Street and Girard Avenue in Brewerytown props open its doors on hot days to cool down members exercising inside. The open doors piqued the curiosity of some kids last month, who cut through the gym while a class was going on.

What happened next depends on whom you talk to, but people in this rapidly changing neighborhood agree that it didn't have to go so far, with bats drawn and a 14-year-old taken away by ambulance in handcuffs.

A skirmish between gym members and nearby residents broke out outside the gym. Kobie Xavier, a trainer at the gym, said he was hit on the head with a folding chair as he tried to defuse the incident.

"It was a horrible situation, and it stems from the fact that we don't know each other," Xavier said. "There were two groups who did not understand each other. We didn't do the groundwork beforehand to be able to talk to one another, and a stressful situation came up, and we were just incapable of communicating."

Brewerytown is one of the fastest-changing neighborhoods in the city, and over the last five years the median home price there has jumped from $59,000 to $105,000.

Businesses sprouting up along Girard, such as Steelworks Strength Systems, have become symbols of gentrifying. A membership costs upward of $200 a month, and the gym caters mostly to newer residents. It's on a strip with a yoga studio, a bar specializing in craft beers, and a cat cafe.

Such redevelopment has at times widened the divide between newer and longtime residents, who also can be split along other lines: poor and wealthy, black and white.

Xavier said he was leading a workout class on May 11 when 14-year-old Naji Tribble and several other boys cut through the gym. Xavier said he was frustrated and cursed at the boys to get out. The boys started throwing rocks at gym members running up and down North College Avenue as part of a outdoor workout. Others from the neighborhood showed up, some with bats, Xavier said.

A scuffle ensued, Xavier said, which is when he was hit with the chair. Xavier said he saw Tribble throw a punch at a woman whose husband, an off-duty police officer, threw the boy to the ground. Tribble was arrested and charged with simple assault, said Kevin Mincey, the family's attorney.

Mincey said the family was considering a lawsuit.  A police internal affairs investigation has been launched into the actions of the officer, Kevin Furman.

On the 1200 block of North Taylor Street, a few hundred yards from the gym, Alfred Tribble, Naji's father, declined to talk about the incident except to say that his son was recovering at home from a fractured skull. Before a reporter left, he offered something about his neighborhood's new landscape.

"It shouldn't be where businesses in this area don't embrace the community," Tribble said. "My son can go in any store that's been on Girard Avenue — not the new ones,  the new bars that you come and get drunk at — but any of the stores on Girard that have been there over 20 years and be fine. But over there, we're not welcome there."

Brian Terpak, the gym's owner, was not around for the melee. He worries about his gym being villainized. In the days following a Philadelphia Magazine article that first reported on the incident, some people stopped and took photos outside. Terpak, a former history teacher in the Philadelphia School District, lives in the neighborhood and said the gym raises money for local after-school and summer programs.

"My next step is to move forward with openness and peace, and to figure out a proper dialogue," Terpak said. "I don't want anyone to feel like we're taking anything from anyone. I feel there's a fear that something is being taken."

Edward Butts, 52, has lived on 25th Street, about three blocks from the gym, since he was 10.

His section of the neighborhood is one with fewer new homes, a nearby public-housing complex, and some drug activity, neighbors say. The residents stick together, and Butts shakes his head when asked about the gym.

"I'll smile and say hello walking by, and they just look at me like, 'Why's he doing that?' I do think they're prejudiced," Butts said. Butts said his niece, who is black, was told to apply online for membership in the gym, while a white neighbor was able to sign up in person.

Terpak sighs when asked if this happened. All are welcome at the gym, he says, and he frequently directs people to apply online if he's working with clients when they come by.

It's an example of how perceptions about places can grow, he said.

West Girard Avenue was a busy retail district until the crack cocaine epidemic in the 1980s, leaving it as the dividing line between Fairmount and Brewerytown.

The change has been dramatic.

Since 31-year-old Kellan White moved to Brewerytown with his wife in 2016,  a spin studio has replaced a hair salon, a hat store has become a pizza place, and the couple have had their choice of breweries and restaurants serving $9 craft beers and $14 hamburgers.

"The stores that were in Brewerytown 10 years ago are leaving, and I think there's something to be said about, yeah, everyone gets along because not everyone is invited to the party," White said.

David Waxman, a founder of MM Partners, a primary developer in the neighborhood since 2001, said his company had always sought a mix of lower- and higher-end retail options.

"We look to bring retail business that does not want to be trendy but service-oriented, that old-time and new-time residents can go to," Waxman said.

MM Partners leased space to Dollar Tree, which recently opened a store just up the street from the gym. Coming soon are a restaurant at 28th and Girard and a dog day-care business. At a Thursday night civic association meeting, 10 developers presented projects, most for housing developments.

Waxman said he also looks for businesses that will be good neighbors. Many of them find ways of engaging with the community, he said.

The local bicycle shop repairs children's bikes free, and a sign on the window of the yoga studio reads: "Our Doors Are Open to All People, All Races and Ethnicities, All Gender Identities, All Sexual Preferences, All Political Views, All Economic Statuses…the only thing we don't tolerate is intolerance!"

Darnetta Arce, executive director of the Brewerytown-Sharswood Civic Association, said she wants to ask businesses about offering discounts to neighbors — a 10 percent off coupon or a free pizza, "maybe a free workout day," she said.

"It's one way to connect the community and businesses," she said. "Sometimes you don't know what services you have in your own community or what a place even is."

Take the brewery Crime & Punishment, whose name confused several older residents at first, Arce said.

Arce stressed that the brawl outside of the gym was not the norm. People mostly get along. "After it happened, I noticed they closed the big glass door," Arce said of the gym. "I saw today the doors were open again."