The Pittsburgh Bureau of Fire (PBF) provides fire suppression and prevention for the City of Pittsburgh, as well as AED response on high priority medical details. In all, the bureau is responsible for 55.5 square miles (144 km2) with a population of 305,841 as of the 2013 Census estimation. The Bureau was the first fire department in the United States to unionize and thus has an International Association of Fire Fighters (IAFF) number of 1. The Fire Bureau provides rescue services to the City of Wilkinsburg and Ingram Boro through the use of two engine companies.