(DENIS POROY ~ Associated Press)
The magnitude-7.2 temblor struck just south of the U.S. border near Mexicali, killing two people and destroying dozens of businesses and homes there and severely injuring another in the neighboring California town of El Centro.
In Calexico, the hardest-hit U.S. city, the quake damaged nearly 80 percent of the city's historic downtown area, authorities said. Three tanks holding the city's water supply were damaged, City Manager Victor Carrillo said.
City officials asked residents to limit water use to essential bathing, cooking and washing.
The quake was the latest blow to a region struggling with the state's highest unemployment rate, said Hildy Carrillo, executive director of the Calexico Chamber of Commerce.
"It will be months before downtown is back," Carrillo said. "It's a mess."
Philip Kim and his family spent much of the night picking up bottles of shampoo, lotion and beauty products at his Best Price beauty products store. The downtown area is made up primarily of discount and 99-cent-type stores.
"It's a hard situation and sales were just picking up in March," Kim said.
He said 90 percent of his customers were from Mexicali and he was worried they wouldn't come back for a while from the bustling commercial center along Mexico's border with California.
Sal Farah, 62, spent the night in his 50-year-old downtown Yturralde Furniture store, fearing it could be looted since the giant storefront windows were knocked out by the quake.
"I didn't get much sleep, especially in the morning when it shook hard again," Farah said, standing in the store littered by broken vases, lamps and shattered knickknacks. They planned to board up the windows later Monday.
One person was critically injured in El Centro, Imperial County fire chief Tony Rouhotas said, though he would not release other details about the person.
It was not immediately clear if the victim was the same person who was hit in the head with a car wash sign Sunday.
Scientists measured about 100 aftershocks early Monday, said seismologist Kate Hutton at the California Institute of Technology in Pasadena. Statistically, there will be one aftershock of around 6.0 and perhaps 10 of 5.0 or larger, she said.
The U.S. damage appeared to be limited to California's southeastern Imperial Valley in what was one of the strongest earthquakes to hit the region in decades. The shaking was felt hundreds of miles away in Phoenix and Las Vegas.