Once a minor player in the drug crisis, the man-made narcotic — about 50 times stronger than heroin — is directly linked to thousands of overdoses and a shocking rise in fatalities nationwide, a trend that is particularly noticeable in the nation’s urban areas.

In 24 of the nation’s largest cities and the counties that surround them, fentanyl-related overdose deaths increased nearly 600 percent from 2014 to 2016, according to county health departments nationwide. According to overdose records in those cities reviewed by The Washington Post, there were 582 fatal overdoses linked to fentanyl in 2014, a number that soared to 3,946 last year. Officials estimate there will be a much higher number of fatal fentanyl-related overdoses in 2017.