I didn’t go to Kensington at night on Code Blue days in December, when the temperatures were dangerously cold. But the addicts were still there. They set up burn barrels to keep fires going, and the city opened emergency warming rooms. Even when the temperatures dropped to single digits, many of the addicts refused go to a shelter. For some users, opioid withdrawal was worse than the possibility of freezing to death.

This January, Gov. Tom Wolf signed a statewide disaster declaration, the first of its kind for a public-health emergency in Pennsylvania. There had been more than 1,200 overdose deaths in Philadelphia in 2017 — a 34 percent rise from 2016. Wolf pushed the state to roll back regulations that might be stopping users from getting help, like ID and sobriety requirements for shelters and treatment facilities. Instead of sending overdosed people back out onto the street, the city hired recovery specialists in the E.R. to talk to them about treatment. It handed out tens of thousands of doses of Narcan. It sent a van into the neighborhood to offer recovery services. It gave residents blue light bulbs for their porches, because the light seemed to make it harder for heroin users to find a vein.

Shanta Schachter, a community development consultant who was hired by Conrail during the cleanup as a liaison between the company and neighborhood organizations, watched the new encampments grow throughout the winter. Months before the Conrail cleanup began, she attended community meetings and chatted with neighbors. She had encouraged residents to take control of Kensington by planting trees in vacant lots, building fences, painting abandoned buildings, installing streetlights. During the cleanup, she was hopeful, but after she drove through the tunnels, she was worried about the addicts living there. “It’s just such an incredible amount of suffering,” she told me. “It’s not like people are getting better. There aren’t resources to help the people who are addicted now. I don’t think anybody really knows how to get the addicts off the streets. It can’t just be new beds, or recovery services, or anything else. It has to be everything.”

The city was willing to try almost anything. In January, the Department of Public Health announced that the city would “encourage organizations to develop” supervised-injection sites, where people can bring their own drugs without fear of arrest and inject under the care of a medical team. There are roughly 120 of these injection sites around the world — although none in the United States — and research has shown that they reduce overdose deaths, connect addicts to long-term care and help keep neighborhoods clean of needles. There has never been a fatal overdose at an official safe-injection site. The Justice Department made it clear that it would view any such place to be in violation of federal drug laws, but Ed Rendell, the former Pennsylvania governor and Philadelphia mayor, threw his support behind a nonprofit group trying to establish one.

At one community meeting this March, city officials explained the idea to residents. The clinic would be located where the most overdose deaths occurred, and that very likely meant Kensington. Many of the overdose victims were white men, though, and some of the minority residents didn’t think it was fair. They worried that establishing a supervised-injection site in the neighborhood would condemn it to a permanent future of drug use. Brooke Feldman, a social worker, had planned to bring a homeless user named Johnny to the meeting, but when she went to the Tulip Street underpass that morning, he had already died of an overdose. “He said he would use the site and wanted to be a part of the conversation,” Feldman told me. “He didn’t even live to be able to do that.”

Dan Martino, a community organizer who put together a march for overdose awareness, had been lobbying for a supervised-injection site for years. “We already have unsafe injection sites on every street corner in the city, and it’s not working out,” he told me. “It has to be easier to get help than heroin.”

In February, on a concrete stoop on East Tusculum Street near the Kensington Avenue tunnel, two sisters, Nancy and Dawn, watched the addicts. Dawn wore a green T-shirt that read, “Dawn’s drinking club,” and her blond hair was high in a ponytail. “Almost everybody I grew up with is either an addict or dead,” she said. “I’m like the only one.”