The 1906 Earthquake and Fire affected the whole Bay Area but the main places it affected were Oakland and San Francisco.
The 1906 earthquake was a VERY large earthquake in the early 1900s. Its score on the richter scale was "values from 7.7 to as high as 8.3 have been proposed." as said on wikipedia. To give you an idea of how large that is, there are many small earthquakes in Oakland, and they measure around 3.0 on the richter scale. The largest recent Earthquake was the Loma Prieta Earthquake in 1989 which was "in the Santa Cruz mountains, northeast of Santa Cruz and approximately 60 miles (100 km) south of San Francisco. It struck just after 5:00 pm local time and lasted approximately 15 seconds, with a moment magnitude of 6.9." -https://www.britannica.com/event/San-Francisco-earthquake-of-1989
Here are a few eye witnesses stories about what it was like.
"The whole house was creaking and shaking, the chandelier was swinging like a pendulum, and I felt as if I were on a ship tossed about by a rough sea. 'This can't go on much longer,' I said to myself. 'When a house shakes like this, the ceiling is bound to collapse. As soon as the plaster begins to fall, I'll cover my head and accept what comes.' "
- Arnold Genthe,“As I Remember It”
This perpective "Nobody knew what to do and everybody seemed rattled. The fire was rapidly increasing and at intervals slight earthquakes would cause small sized panics. People would rush to the middle of the street between the car tracks and stay there quite a while after the shock had passed away. We had stayed in the house and ran down stairs at every slight shock."
-Lloyd Head,“One Boy’s Experience”
"Earthquakes come like Christmas – once a year – or, rather, once a century. I have lived in Japan, Honolulu and Naples, and these are the earthquake countries. They quake only now and then, and as a rule more people die from stale fruit in the tropics than from earthquakes. An earthquake is as innocent as a kid. Keep out of the way of the kid. In truth I know nothing in nature quite so innocent as an earthquake. Look around you in every little village here. Half a dozen houses, and half a dozen happy families, but everything built close down to the ground, with all California to build over. I don't see why we have to crowd into one little plot of land."
- Joaquin Miller,“A Fire So Richly Fed”
In the book Oakland Tales, the two main characters, Jada and Ernesto travel back in time to different years in the past in Oakland. One of those times is 1906. They see how there was child labor and how the way that life worked back then. They then saw the earthquake happen and they helped the people by cooking food and handing it out to the poor. This affected the characters in a positive way because it made them realize how they could help out and be useful in situations like this.