[3] These variations generally relate closely to the underlying geology, with higher intensities recorded where there was either artificial fill or alluvium, although there were some exceptions.

[1] Three people were killed by falling debris in the Duwamish valley floor area of Seattle,[6] and four others died from heart attacks.

The two Boeing plants at Renton and Seattle, both built on artificial fill and mudflats, suffered major damage.

[4] The State Capitol building in Olympia suffered cracking to the dome and supporting buttresses, leaving it in a condition where a major aftershock could have caused complete collapse.

The Tacoma Narrows Bridge was closed for 30 minutes as a precaution but reopened with only damage to light fixtures and weather seals on cables.