1994 Northridge earthquake

The 1994 Northridge earthquake was a moment 6.7 (), blind thrust earthquake that occurred on January 17, 1994, at 4:30:55 a.m. PST in the San Fernando Valley region of the City of Los Angeles. The quake had a duration of approximately 10–20 seconds, and its peak ground acceleration of 1.82 g was the highest ever instrumentally recorded in an urban area in North America. Shaking was felt as far away as San Diego, Turlock, Las Vegas, Richfield, Phoenix, and Ensenada. The peak ground velocity at the Rinaldi Receiving Station was , the fastest ever recorded. Two 6.0 aftershocks followed, the first about one minute after the initial event and the second approximately 11 hours later, the strongest of several thousand aftershocks in all. The death toll was 57, with more than 9,000 injured. In addition, property damage was estimated to be $13–50 billion (equivalent to$24–93 billion in 2021), making it among the costliest natural disasters in U.S. history. The earthquake struck in the San Fernando Valley about northwest of downtown Los Angeles. Although given the name "Northridge", where the quake was believed to have been centered and substantial damage occurred, the actual epicenter was pinpointed in the neighboring community of Reseda within several days. The United States Geological Survey placed the hypocenter's geographical coordinates at and at a depth of . It occurred on a previously undiscovered fault, now named the Northridge Blind Thrust Fault (also known as the Pico Thrust Fault). Several other faults experienced minor rupture during the main shock and other ruptures occurred during large aftershocks, or triggered events. Damage occurred up to away, with the most damage in the west San Fernando Valley, and the cities and neighborhoods of Santa Monica, Hollywood, Simi Valley, and Santa Clarita. The Historic Egyptian Theater in Hollywood was red-tagged and closed as was the Capital Theater in Glendale due to structural damage. The exact number of fatalities is unknown, with sources estimating the number to be 60 or "over 60", to 72, where most estimates fall around 60.