Designed to help prevent injection-drug users from sharing needles and spreading HIV and other blood-borne illnesses and from overdosing, North America's first supervised heroin injection site opened Monday in Vancouver, Canada, Agence France-Presse reports. Organizers estimate that up to 800 injection-drug users will use the site each day. The facility, modeled after similar sites in Europe and Australia and located in a section of the city with a large number of drug addicts, will include a staff of 16 nurses and several counselors who will offer medical treatment, watch for signs of overdoses, and give recommendations for drug-treatment programs. Free needles also will be provided. The Canadian government approved the site in June after an 18-month study. The site is run by the Vancouver Coastal Health Authority and funded by the federal and British Columbia governments.