Emergency Services Unit

An emergency service unit (ESU), alternatively emergency service detail (ESD) or emergency service squad (ESS), is a type of unit within an emergency service, usually police, that is capable of responding to and handling a broader or more specific range of emergencies and calls for service than regular units within their organization, such as rescue, emergency management, and mass casualty incidents. They are similar to police tactical units, fire department technical rescue, and incident respon