The San Francisco earthquake of 1906 was marked by catastrophic destruction and significant developments. It struck on April 18, 1906, and had a magnitude estimated between 7.7 and 8.3, followed by numerous devastating fires. The city was largely built with wooden structures, which rapidly caught fire, resulting in widespread loss of property and life. An estimated 3,000 people died, and around 80% of the city was destroyed. The earthquake prompted major reforms in building codes and urban planning as San Francisco rebuilt. It also spurred advancements in seismology, as scientists sought to better understand earthquakes and implement measures to mitigate future disasters.