This document presents information on air attacks and on civil defense preparations and accomplishments in the city of Hamburg, Germany, up to the time of the large scale attacks that began on July 25, 1943. A map summary of bombed sites; numerical and graphical summaries of the air attacks; a map of security police groups, sectors, and precincts; and a diagram of the organization and structure of a chronology of police bulletins, pamphlets, orders and organization plans for emergency service situations. A civil defense system was developed in response to preconceived of shelter rooms, to poison gas protection, to blast protection, to shelter habitability, and finally, to the recognition of fire as the major hazard to be faced.