The Kensington neighborhood of Philadelphia - known as 'ground zero' for the city's drug epidemic - is in crisis due to widespread abuse of an animal tranquilizer called xylazine.

Addicts are shooting up in broad daylight, hunched over in a stupor or passed out on the streets. Many have raw, gaping wounds in desperate need of medical attention. And there are needles, syringes and garbage littered across the sidewalks.