"All of the buildings fell at once; no one first," a man named Green Thompson told an investigator into the 1906 earthquake in Santa Rosa. He added the dust was so great on Fourth street he couldn't see.

Yes, the buildings that collapsed downtown were almost all brick, and mostly built 1883-1885 during the town's first building boom. Yes, unreinforced masonry buildings are not particularly earthquake friendly. But it has always rankled that the official 1908 State Earthquake Commission report put the blame on our ancestors not knowing the basics of building construction:

In general, inquiries as to direction of fall of buildings met no definite answer...many told me that there was no direction of fall; that the buildings simply crumbled to the ground. The Masonic Temple and the Theater, I was told, fell so directly downward "that the debris did not extend beyond the walls 10 feet in any direction"...The great damage in Santa Rosa may be accounted for by the physiographic conditions and by the weakness of the buildings in many cases. The sand for mortar has usually been obtained from the creek and contains considerable loam. Some of the mortar seems to have been made with good sand and with cement...usually throughout the wrecked area the mortar taken from the walls is easily crumbled to incoherent sand by pressure of the fingers.

It's understandable that too much loam is undesirable (although there's a 1903 researcher who says up to 10 percent dirt is actually beneficial) but we don't know what the investigator meant by "considerable", nor how he learned this. That goes to the heart of the question: before all the buildings fell down, did anyone know the mortar was weak? If it was always crumbly, that would have been apparent soon after the first brick buildings went up in 1883, and surely they would not have continued making the same mistake for another two years.

The rest of this article can be read at the SantaRosaHistory.com website. Because of recurring problems with the Blogger platform, I am no longer wasting my time formatting and posting complete articles here. I will continue to create stubs for the sake of continuity, but will be publishing full articles only at SantaRosaHistory.com. - Jeff Elliott


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