An earthquake that shook a swathe of Southern California forced a community out of their homes after firefighters discovered foundation problems that made the buildings unsafe.
Fire crews red-tagged 20 apartment units in a building in the Orange County city of Fullerton after finding a major foundation crack. Structural woes including broken chimneys and leaning were uncovered in half a dozen single-family houses, which were also deemed as unsafe to occupy until building inspectors could give the all-clear. The damage displaced 83 people.
Despite the evacuations, yesterday's magnitude-5.1 quake centred about 25 miles south of central Los Angeles frayed mostly nerves.
The quake was preceded by two smaller foreshocks and more than 100 aftershocks followed, including a magnitude-4.1 that hit last night, the largest in the sequence so far. No injuries were reported.
Residents were inconvenienced and some lost valuables, but "thankfully the damage wasn't greater", said Chi-Chung Keung, a spokesman for the city of Fullerton.
Business owners in Orange County spent the aftermath sweeping up shattered glass and restocking shelves. Utility crews worked to restore power and shut off gas leaks and water main breaks. A rockslide in the Carbon Canyon area of nearby Brea also caused a car to overturn. The occupants had minor injuries, and the road remained closed to traffic.
The Red Cross opened a shelter in neighbouring La Habra and closed it once 38 people who stayed overnight returned home.
In Fullerton, some people will have to stay elsewhere until building inspectors can check out the red-tagged apartments and houses and give an all-clear.
Another 14 residential structures around the city suffered lesser damage, including collapsed fireplaces.
A water main break flooded several floors of Brea City Hall, and the shaking knocked down computers and ceiling tiles. It was not immediately clear if City Hall would reopen tomorrow.
Yesterday's jolt was the strongest to strike the greater Los Angeles region since 2008. Southern California has been in a seismic lull since the deadly 1994 Northridge earthquake killed several dozen people and caused 25 billion dollars (£15bn) of damage.
The latest quake hit a week after a magnitude-4.4 centred in the San Fernando Valley shook buildings and rattled nerves.
It appeared to break a one-mile segment of the Puente Hills thrust fault, which stretches from the San Gabriel Valley to central Los Angeles and caused the 1987 Whittier Narrows quake that killed eight people. The rupture lasted half a second, scientists said.
US Geological Survey seismologist Lucy Jones said it was unclear whether Southern California was entering a more active seismic period. "We have been in a really quiet time. It can't stay that way," she said.