By Amanda Holpuch, The Guardian

For five years, a secret supervised drug injection site has operated in the US, allowing drug users to inject more than 10,000 times in a sterile, protected environment.

The illegal operation is modeled after similar, legal sites in Canada and Europe, which seek to provide drug users with a place to get clean supplies, connect with social services and avoid overdosing in a dangerous place.

study of the underground site published in the New England Journal of Medicine online on Wednesday revealed how lives could be saved if the US were to sanction such facilities.