To really comprehend the heroin crisis consuming Kensington, climb five flights of crumbling stairs and a narrow, rusting ladder to the roof of the shuttered carpet mill at A and Indiana.

On the street, the crush of the drug trade overwhelms – a disorienting maze of scoring and selling and the small signs of hope found amid the suffering.

From above, the maze reveals itself. It's not even a maze. The core of the crisis stretches along seven blocks of Indiana: the through line between the heroin camp at the Gurney Street train gulch to Kensington Avenue where suburban kids get off the El for drugs and never leave.

"If we can talk about it as a health crisis, then there is an epicenter to that the crisis – and that's it right there," said Casey O'Donnell, the president of Impact Services Corp., a neighborhood revitalization organization working to transform the hulking carpet mill into a community-focused service center with housing, job training, and health services – a beacon in a neighborhood so desperate for them.

The crisis will deepen this summer, and from the roof, you can see it all play out.

There is Gurney Street. In the weeks ahead, the city and Conrail plan to at last close off a place inhabited by 75 to 100 people at rock bottom: addicted to heroin, often suffering from mental illness, and most without even identification that could speed their way into treatment. It also will eliminate a thriving drive-in drug market. The next closest market? Hope Park, where the name is almost too painfully ironic to write at this point.

At Hope Park, the open-air drug markets are so congested with customers from all over that toddlers get scolded by their parents for unknowingly echoing the sales cries of the dealers – and the brand names of the heroin they hawk.

"What you need?"

"Skywalker…Suicide…Little Miami!"

Four blocks east at McPherson Square, where national attention has focused on the plight of the historic library at its center – and the librarians who were saving overdose victims' lives with Narcan on a near-daily basis – the subsequently increased police presence has pushed the young out-of-towners who shot up on the library lawn deeper into the neighborhood. Toward Hope Park.

From above, you can see the pincers closing in on the park and the blocks around it. This is now the place where the city has a choice: It can continue to push around a problem the way it has for decades – clean up one block, cede the next. Or respond in the overwhelming way that an overwhelming crisis demands: Dig in with the sustained, permanent efforts needed to reach those suffering from addiction, and support the groups that have been fighting for the neighborhood for years.

Up here, the stakes are clear.

You can see Swanson Street, a side street wedged between the train tracks and Hope Park. Amid the suffering, Swanson Street is an oasis – as much as it can be. Every morning, block captain Mariana Bernard, who is 69, ropes off Swanson for the city's summer Play Streets program. As the children play, Mariana and Gladys Moya, a neighbor whom Mariana calls her "bodyguard" – for her prized scowl and the skull ring she wears – shoo away the users who duck down Swanson to get high, or who now sleep along the ledge of the old carpet mill, already having moved on from Gurney Street.

"We tell them, 'No, no, no, this is a good block,' " Gladys said, showing her ring. But as the street swells with users and sellers, the ladies can only yell so much.

And you can also see the homes that line Hope Park – the ones with the cruelest views.

Anna Santiago, who is 70 and lives next to the park, can't help but weep when she looks out through the bars of her kitchen window onto Hope Park's garden, now overgrown and littered, often with needles. She has lost three sons to violence and the drug trade in the neighborhood. And for so many years, her husband, Victor Ortiz, tended to his rows of green peppers, cabbage, cucumbers, and tomato plants – and his beloved roses. But Victor, who worked as a Philadelphia Housing Authority inspector, died 10 years ago. The park is just too dangerous for Anna.

"Bonito, bonito, bonito," Anna said, said wiping her tears, as she showed a photo of Victor in his garden. Beautiful, once.

Across the park, Cynthia Robles, who is 38, awakes each morning to the ever-increasing bustle of the Hope Park heroin markets. These days, she questions if there is any hope at all. She recently offered her oldest son, Sean, who is 18, an ultimatum: Stop dealing or leave. Pulled by the lure of streets around the park, Sean left.

Now, Robles only comes over when she sees Miss Jenn making her rounds. Three years ago, Jennifer Morales-Torres, who is 53 and grew up in the neighborhood, and her husband, Miguel Torres, started a friends' group to try to clean up the park.

It was Morales-Torres who back then gave the park its optimistic name: "Even amid all this, there is still hope," she says. But on Thursday she celebrated a small victory: Someone had painted over a park sign that had been vandalized: "Dope Park."

And heading east toward McPherson, you can see all the corners in between, each offering its own sad tableau of a growing crisis.

Like Kip and Cambria, where Pastor Cookie Sanchez of the Iglesia Del Barrio church keeps her Narcan spray in her pocket now, even during sermons, lest she need to run outside again and revive someone. And across the street, where a dealer named Aldo said the neighborhood teens slinging heroin on the corner, some to support their own parents' habits, were making easy money now.

"Like $400 or $500 a shift," Aldo said.

And, on every corner, the suburban kids who are propping those sales.

There is Dustun, who is 23 and from Bucks County and now sleeps on a bean bag in a Kensington lot with a plastic rosary around his neck, a desperate fentanyl habit, and a right foot badly swollen from a MRSA infection. He wasn't concerned that either could kill him, he said. And there is Gregory Antczak, who is 35, and worked in trendy Center City restaurants like Dark Horse and Black Sheep before his habit overtook him – and he began sleeping on Kensington Avenue. He was making his way past McPherson Square, with a broken collarbone and scraped forehead from a recent fall. He limped down the avenue.

Back on the roof, O'Donnell and Patricia Codina, from Impact Services, stepped away from the view to talk about what needs to be done to stem the crisis. After initially promising two days of outreach at Gurney Street, the city has pledged to support a mobile outreach center outside the carpet factory to last all summer. That's what this enormously complicated crisis needs. The days for well-intentioned, albeit short-lived, support are far past. The day when we figure out a comprehensive solution is still ahead of us. A permanent presence, not just for the summer, to help the human beings caught in this crisis is going to get us there.

"This," O'Donnell said, "is an opportunity here that we can't miss."