On January 17, 1994, at 4:30 am, a 6.7 magnitude earthquake shook the ground in the San Fernando Valley for approximately 10-20 seconds. A peak ground acceleration of 1.82g was the highest recorded in an urban area of North America.
The earthquake was so strong that it was felt in San Diego, Turlock, Las Vegas, Richfield, Phoenix, and Ensenada. In the Northridge neighborhood, the epicenter was believed to be in the San Fernando Valley, 20 miles northwest of downtown Los Angeles. However, it was later discovered that the epicenter was in the town of Reseda.
The Northridge earthquake was also more destructive than the quake of 71, because of its location, directly below the San Fernando Valley. The earthquake caused at least 72 deaths, and over 9,000 injuries, and displaced 125,000 people. In addition, the Northridge Fashion Center and California State University, Northridge, were damaged, as the parking structure had collapsed.
The quake gained worldwide attention due to the collapse of the Santa Monica Freeway, Interstate 10; it is known as one of the busiest freeways in the US. It took months to repair, causing even more traffic than usual in the Los Angeles area.
One of the most unusual things with the earthquake was an outbreak of coccidioidomycosis, Valley fever, in Ventura County. A respiratory disease that is caused by inhaling spores of the fungus. Many believed the spores were carried in the giant clouds of dust created by seismically triggered landslides.
Hospitals were affected by structural damage and had to transfer patients to other hospitals. However, it did create a new law to be passed that all hospitals in California need to be earthquake resistant, and as of 2009, the hospitals have complied.
The earthquake was the most expensive natural disaster in California's history, estimating 20 billion in damages and 49 billion in economic loss.