Three units of the 2nd Marine Division had key roles during various periods of the occupation, as indicated below: @ 2nd Regimental Combat Team (RCT), 23 September to early November 1945 -e harbor and most of the nearby county east of the Urakami River. 6th RCT, 23 September to December 1945 -- @ The zone of occupation included the east side of the Nagasaki The zone of occupation included the west side of the Nagasaki harbor and most of the nearby county west of the Urakami River. 10th Marine Regiment, November 1945 to June 1946, when the Marine Corps occupation of Nagasaki came to an end -- The Regiment assumed the responsibilities first of the 2nd RCT upon its departure from Nagasaki and then of the 6th RCT. Specific billet locations have not yet been identified for all division units, which also included the 8th RCT, a Headquarters Battalion, Service : Troops, an Engineer Group, a Tank Battalion, an Observation Squadron, and some smaller organizations. It is known, however, that the 2nd RCT was billeted in the Kamigo barracks and the 6th RCT in the Oura barracks, both shown in figure 19. The other troops also were in areas well clear of the hypocenter, which was cordoned off by the 2nd and 6th RCTs upon their arrival in the area. Section 6.4 summarizes doses for participating units of the 2nd Marine Division, for Navy personnel who transported the Marines to Nagasaki and evacuated some 9,000 Allied former POWs during 1 through 13 September 1945, and for another 1,100 Navy support personnel. 6.4 RADIATION DOSES. Few world events have been as thoroughly documented at the time and as intensively and continuously studied since by as many different groups of scientists as the atomic bombings and related radiation exposures at Hiroshima and Nagasaki. Thus, the patterns of residual radiation are well understood. This understanding, with other information, provides a solid basis for radiation dose determination. 161