slough and marsh, known as the Pipeville Slough, was the ground on which
the City Hall was built, and which was originally a burying ground. Sand
from the western shore had blown over and drifted into the marsh and
hardened its surface.

When the final grading scheme of the city was adopted in 1853, and
work went on, the water front of the city was where Clay Street now is,
between Montgomery and Sansome Streets. The present level area of San
Francisco of about three thousand acres is an average of nine feet
above or below the natural surface of the ground and the changes made
necessitated the transfer of 21,000,000 cubic yards from hills to
hollows. Houses to the number of thousands were raised or lowered,
street floors became subcellars or third stories and the whole natural
face of the ground was altered.

Through this infirm material all the pipes of the water and sewer system
of San Francisco in its business districts and in most of the region
south of Market street were laid. When the earthquake came, the
filled-in ground shook like the jelly it is. The only firm and rigid
material in its millions of cubic yards of surface area and depth were
the iron pipes. Naturally they broke, as they would not bend, and San
Francisco's water system was therefore instantly disabled, with the
result that the fire became complete master of the situation and raged
uncontrolled for three days and nights.

Although the earthquake wrecked the business and residential portions
of the city alike, on the hills the land did not sink. All "made ground"
sank in consequence of the quaking, but on the high ground the upper
parts of the buildings were about the only portions of the structures
wrecked. Most of the damage on the hills was done by falling chimneys.