How disastrous was the San Francisco earthquake?
The San Francisco earthquake of 1906 was the worst quake ever to hit an American city. It struck on April 18 at 5:12 A.M. and lasted 20 seconds, with 45 seconds of aftershocks (smaller quakes that follow a larger quake). The quake cracked gas lines (pipes that deliver natural gas) to homes and businesses, causing a fire that raged for three days and destroyed 75 percent of the city. The entire business district was leveled and 75 percent of homes were burned down. Three thousand people lost their lives and 250,000 to 300,000 people were left homeless. It is not known how large the San Francisco earthquake was since it occurred before the invention of the Richter scale. (Used to measure the magnitude of earthquakes, the Richter scale has graded steps beginning with 1 and ending with 10. Each step is about 60 times greater than the preceding step.)…
