At 4:31 AM on Monday, January 17, 1994, the most expensive earthquake, and one of the most expensive natural disasters in U.S. history, shook the Southern California region. Although this earthquake is considered "moderate", with a magnitude of 6.8 on the Richter Scale, the location of the epicenter in a highly populated suburb of Los Angeles caused 57 deaths and injured approximately 1,500 people. Until the time of the earthquake, the Northridge fault line was unknown, calling into question the accuracy of earthquake maps.
The Northridge Earthquake caused more than $10 Billion in damage. Of the 66,546 buildings inspected, 6% were "red tagged" (severely damaged) and 17% were "yellow tagged" (moderately damaged).
Some of the most traveled freeways in the nation were closed for several months and 11 major roads providing access to Los Angeles were damaged. Many residents and business were displaced to adjacent (less damaged) areas, while repair projects were completed.