U. S. GEOLOGICAL SURVEY 
BULLETIN NO. 324 PL. XXIX 
A. EARTHQUAKE CRACKS IN WALL OF VAULT, CALIFORNIA CASKET 
COMPANY'S BUILDING, SAN FRANCISCO. 
Photograph by Richard L. Humphrey. 
11. COLLAPSE OF FLOOR PANEL, CAUSED BY LOAD FALLING FROM A FLOOR ABOVE, THIRD 
FLOOR OF /ETNA BUILDING, SAN FRANCISCO. 
The failure of the upper floor was due to the softening by heat of reenforcing steel bands. Photographs 
by Richard L. Humphrey. 
