They Entered Treatment. Drugs, Overdoses and Deaths Followed.

Amanda Vlakos had been living for years in rat-infested abandoned buildings in Baltimore, fighting an addiction to opioids, when she learned of a possible escape: a drug-treatment program that offered patients free housing.

Sober when they arrived, Ms. Vlakos and her boyfriend were placed in a barely furnished two-bedroom apartment with a succession of strangers who often used drugs. She relapsed after a month. Roommates kicked in doors, flooded the bathroom and sold drugs out of their unit. Even some of the house managers got high, residents said.

On Sept. 5, after nearly two years in the program and with nowhere else to go, she sent a desperate text message to a former counselor. “I feel so helpless and alone,” wrote Ms. Vlakos, 34. Two weeks later, she died of an overdose.

PHA Healthcare, the company whose program Ms. Vlakos entered, collects millions of dollars a year to treat hundreds of people struggling with addiction. But many of its patients have not gotten better. Instead, placed by the company in what are effectively government-funded drug houses, they have relapsed, fallen deeper into addiction and sometimes died, an investigation by The New York Times and The Baltimore Banner has found.

Baltimore’s drug epidemic is the deadliest ever seen in a major American city. A Times/Banner examination in May showed that top city officials reacted with little urgency as the death rate mounted, letting key public health efforts stall.