This documentary, produced on the 100th anniversary of the earthquake, is an interesting review of the disaster.
However, it is mistakenly labeled as the "worst ever natural disaster" in an urban American setting.
There were approximately 3000-6000 deaths in the earthquake; in the Galveston hurricane of 1900, there were approximately 6000-12000 fatalities. San Francisco largely recovered, but Galveston was never the same.
The earthquake was a horrible tragedy, but there's no need to to forget an episode of even greater devastation.