Opioids, mainly synthetic ones like fentanyl, are the leading driver of overdose deaths, which killed more than 70,000 people in the United States in 2017. In the city alone, the rate of overdoses has more than quadrupled in the last four years, from 48 in 2015 to 199 in 2018. This year, there have been 44 overdoses, one of them fatal.