drug deaths to record highs, has infiltrated virtually every channel of the illicit drug supply and turned it more toxic than ever.

In this city and across the U.S., traffickers are making fentanyl, primarily produced in Mexico, the dominant substance for opioid users craving a fix.

The synthetic drug is killing users who fear its strength but can’t easily find alternatives, as well as those seeking it out to feed their rising tolerance to prescription painkillers or heroin.