On August 11th, 1945, two days after the bombing of Nagasaki, a message was
dispatched from Major General Leslie R. Groves to Brigadier General Thomas
F. Farrell, who was his deputy in atomic bomb work and was representing him
in operations in the Pacific, directing him to organize a special Manhattan
Project Atomic Bomb Investigating Group.

This Group was to secure scientific, technical and medical intelligence in
the atomic bomb field from within Japan as soon as possible after the
cessation of hostilities. The mission was to consist of three groups:

1. Group for Hiroshima.
2. Group for Nagasaki.
3. Group to secure information concerning general Japanese activities in
the field of atomic bombs.

The first two groups were organized to accompany the first American troops
into Hiroshima and Nagasaki.

The primary purposes of the mission were as follows, in order of
importance:

1. To make certain that no unusual hazards were present in the bombed
cities.

2. To secure all possible information concerning the effects of the bombs,
both usual and unusual, and particularly with regard to radioactive
effects, if any, on the targets or elsewhere.

General Groves further stated that all available specialist personnel and