Tsunami of April 1, 1946 — Macdonald et al 
the house off the stilts. The few reinforced 
concrete structures in devastated areas suf¬ 
fered little or no damage except that caused 
by flooding. 
The railroads along the northern coast of 
Oahu and in Hilo were wrecked, partly 
through destruction of the roadbed, but 
largely because the tracks were shifted off the 
roadbed, either inland or shoreward. Locally 
rails were torn loose, but more generally the 
track was moved en masse, a motion probably 
aided by the buoyancy of the ties. Coastal 
highways also were partly destroyed, largely 
by undercutting as the water returned sea¬ 
ward, but partly by the direct force of the 
waves. Several highway and railway bridges 
were destroyed. Most appear to have been 
partly or entirely lifted from their founda¬ 
tions by the rising of the water under them. 
The head of the pier at Waianae, Oahu, was 
damaged in the same manner. At the Wai- 
luku River, in Hilo, an entire span of the 
steel railroad bridge was torn loose and 
carried 750 feet upstream, passing under but 
not damaging a highway bridge. At Kole- 
kole Stream, 11 miles farther north, an entire 
leg of the high steel railroad trestle was re¬ 
moved and carried upstream about 500 feet. 
Part of the end and much of the shed of 
Pier 1 in Hilo was wrecked by the force of 
the wave. Most of the damage on Pier 2, 
however, resulted when heavy pontoons, 
which had been moored near by, were washed 
across the pier. The wharves at Kahului on 
Maui were flooded, but sustained little struc¬ 
tural damage. 
The upper part of the breakwater at Hilo 
was about 61 per cent destroyed (Plate 1). 
Blocks of rock weighing more than 8 tons 
were lifted off the breakwater and dropped 
both inside and outside it. Destruction was 
limited, however, to the part above water or 
that only slightly submerged. The average 
depth of water over the destroyed sections 
after the wave was only about 3 feet. The 
breakwater at Kahului, Maui, also suffered 
35 
minor damage. At both Hilo and Kahului 
the breakwaters appear to have reduced mate¬ 
rially the height and violence of the waves 
in the enclosed portions of the harbors. 
Many small boats were washed ashore and 
damaged. Railroad cars were overturned on 
Oahu, Maui, and Hawaii. Many automobiles 
were wrecked. The loose stone walls of fish- 
ponds along the southern coast of Molokai 
were partly thrown down. The mill of the 
Hakalau Sugar Company, situated only about 
10 feet above sea level at the mouth of Haka¬ 
lau Gulch on the island of Hawaii, suffered 
severe damage. 
Erosion by the tsunami resulted in the 
partial removal of some sand beaches, in 
some places causing a retreat of the shore 
line for several tens of feet, cutting of small 
scarps, and forming of large beach cusps at 
the heads of beaches; locally, erosion caused 
stripping away of a small amount of soil. The 
erosion was largely concentrated high on the 
beach, severaLfeet above sea level. Some of 
the sand from the beaches was carried inland 
and redeposited. At Haena, Kauai, the high¬ 
way was buried under 4 feet of sand, and 
thinner layers of sand covered roads on 
Oahu. 
Flooding caused much water damage to 
house furnishings and personal property. 
LOSS OF LIFE AND PERSONAL INJURY 
The following table summarizes, by islands, 
the number of persons killed, injured, or 
missing as a result of the tsunami. The fig¬ 
ures were supplied by the American Red 
Cross. Most of the deaths were by drowning. 
By far the heaviest toll was at Hilo, with 83 
known dead and 13 missing. Those listed as 
missing have been missing for more than 2 
months, and must be presumed dead, bring¬ 
ing the total number of probable dead to 
159. Great as it was, this loss of life was 
moderate compared to that in some other 
tsunamis, such as that of 1896 in the Sanriku 
