Photos: Northridge Earthquake, 30th anniversary of the costliest earthquake disaster in U.S. history

On Jan. 17, 1994, at 4:31 a.m. a fault ruptured 9 miles beneath the Los Angeles neighborhood of Northridge. In less than 20 seconds, the 6.7-magnitude quake damaged more than 40,000 structures, resulting in $20 billion in damage and more than $40 billion in economic loss.