stone, with partitions of metal, glass, and plaster. With the exception of
the Nagasaki Medical School and Hospital group, which was designed to
withstand earthquakes and was therefore of heavier construction than most
American structures, most of the reinforced concrete structures could be
classified only as fair, with concrete of low strength and density, with
many of the columns, beams, and slabs underdesigned and improperly
reinforced. These facts account for some of the structural failures which
occured.

In general, the atomic bomb explosion damaged all windows and ripped out,
bent, or twisted most of the steel window or door sashes, ripped doors from
hinges, damaged all suspended wood, metal, and plaster ceilings. The blast
concussion also caused great damage to equipment by tumbling and battering.
Fires generally of secondary origin consumed practically all combustible
material, caused plaster to crack off, burned all wooden trim, stair
covering, wooden frames of wooden suspended ceilings, beds, mattresses, and
mats, and fused glass, ruined all equipment not already destroyed by the
blast, ruined all electrical wiring, plumbing, and caused spalling of
concrete columns and beams in many of the rooms.

Almost without exception masonry buildings of either brick or stone within
the effective limits of the blast were severely damaged so that most of
them were flattened or reduced to rubble. The wreckage of a church,
approximately 1,800 feet east of X in Nagasaki, was one of the few masonry
buildings still recognizable and only portions of the walls of this
structure were left standing. These walls were extremely thick (about 2
feet). The two domes of the church had reinforced concrete frames and
although they were toppled, they held together as units.

Practically every wooden building or building with timber frame within 2.0