Urban search and rescue (abbreviated as USAR, also known as Urban SAR) involves the location, extrication, and initial medical stabilization of victims trapped in confined spaces. Structural collapse is most often the cause of victims being trapped, but victims may also be trapped in transportation accidents, mines and collapsed trenches. In 2007, USAR was legally defined and English fire and rescue services were required by law to deal with An emergency involving the collapse of a building or other structure.