
In USA TODAY's news bureau on the ninth floor of an office tower near Los Angeles International Airport, window blinds shook, and the building rolled in steady waves. The quake was also felt in San Diego. Seismologist Lucy Jones tweeted that quake struck on the San Jacinto fault, one of the most active in the region. She says the same fault produced a magnitude-6 earthquake in 1937 and a 5.3 quake in 1980.

In the past 10 days, there have been two earthquakes of magnitude 3 or higher in the same region. On Tuesday, an emergency dry run of how officials will respond to a tsunami-causing earthquake along the west coast began. On the west side of Los Angeles, about 100 miles from the epicenter, the quake produced a long shaking motion lasting about 30 seconds, but there was no hard jolt. Satff in USA Today's news bureau, on the ninth floor of an office building near Los Angeles International Airport, said window shutters shook and the building structure rolled in waves. Seismologist Lucy Jones tweeted that quake struck on the San Jacinto fault, one of the most active in the region. She says the same fault produced a magnitude 6 earthquake in 1937 and a 5.3 quake in 1980.