There were a few foreshocks and have been hundreds of aftershocks from Friday night's magnitude 5.1 earthquake in La Habra.
The Times' Ken Schwencke produced an interactive map, visible above, that shows the swarm of earthquakes over the last day.
The vast majority of the quakes were in the La Habra, Fullerton and Brea area. But there were also some in Los Angeles County, including Rowland Heights and La Mirada. The strongest was a magnitude 4.1 quake in Rowland Heights on Saturday afternoon.
Experts say the aftershocks should become less prevalent over time.
Across northern Orange County, officials were tallying moderate damage from Friday's quake.
Crews were working to repair broken water mains, leaking gas lines and other damage.
At least seven 8-inch water mains were broken, leaving an estimated 100 homes and businesses without water Saturday morning, officials said.
In the middle of the intersection of Gilbert Street and Rosecrans Avenue in Fullerton, a crew armed with shovels, earth movers and massive stainless-steel water-main clamps labored in a 12-by-20-foot hole eight feet under the pavement.
"We have five leaks as big as this one in this area alone," worker Ed McClain said. "None of us slept a wink last night. We'll keep going until these problems are fixed."
Swaths of Gilbert Street had been undermined by gushing water, leaving bowl-shaped depressions in the roadway.
Among those left high and dry was Sarah Lee, director of a nearby college preparatory business.
"Let me show you what we're dealing with," she said, turning the handle of her bathroom sink's faucet. "Nothing."
Lee then tapped the toilet handle and frowned: "Nothing."
In the nearby city of Brea, which is served by the Fullerton Fire Department, a broken water main caused "moderate to heavy damage" at City Hall, fire Battalion Chief John Stokes said.
In all, more than 70 people remained displaced at midday Saturday -- 54 of them from an apartment complex in the 2600 block of Associated Road where 20 units were red-tagged after the building suffered a cracked foundation, Stokes said.
Cracks up to 2 inches wide could be seen extending roughly 30 feet into the property and building.