Families huddled in parks and parking lots in the northern Mexican border city of Mexicali on Monday after aftershocks from a big earthquake led them to sleep out in debris-strewn streets.  Two people died and more than 200 people were injured when a 7.2 magnitude quake rocked the Mexico-California border area on Sunday afternoon, Baja California Gov. Jose Osuna told a news conference.  The tremor, felt as far north as Los Angeles, cracked main roads, toppled electricity posts and knocked down an empty multistory car park under construction in Mexicali, a prosperous city and busy border crossing. One person was crushed in a collapsed house, the other hit by a falling wall.

Osuna said towns south of Mexicali near the quake's epicenter could be harder hit and 3,500 people whose houses collapsed or were badly damaged would be moved to shelters.  The area was rattled by more than 80 aftershocks in the hours following the quake, the U.S. Geological Survey said.  "With the number of aftershocks we've had, the likelihood of another 6 or 7 magnitude earthquake is very real," Erik Pounders, a USGS geologist, said. "There might be a few structures that just barely made it though and the second one could be the straw that breaks the camel's back."

Hundreds of people camped out overnight as smaller tremors shook buildings with cracked floors, walls and broken windows.  "I wasn't going to put my family at risk. Lots of homes have cracks," said Fermin Garcia, a teacher who slept with her family in a tent pitched between two shopping centers.

Broken gas pipes sparked a number of fires on Sunday, and darkened streets in Mexicali triggered car accidents, but no major buildings appeared to have collapsed.  Power was mostly reestablished on Monday, but many state-run hospitals still lacked electricity and lay patients out on beds in parking lots due to worries over cracked walls.

A highway connecting Mexicali with the nearby border city of Tijuana on the Pacific coast was ruptured by a crack at least a meter (3 feet) deep, according to a Reuters witness.  A liquefied natural gas import terminal south of Tijuana was not damaged however, operator Sempra Energy said.  President Felipe Calderon will visit Mexicali, home to more than a million people and a center for food processing and assembly-for-export plants, later on Monday.

AFTERSHOCKS
Vacationers returning from Easter holidays were stuck in traffic jams and motorists reported difficulty finding fuel.  "Thank God nothing happened to us. Now we just have to wait until the police let us fuel up," said Maria Lopez, who had been waiting four hours to buy fuel to drive to Tijuana.

Sunday's quake rattled nerves in the United States and across tremor-prone Latin America which has been shaken by devastating earthquakes in Haiti and Chile this year.  The relatively shallow quake was centered in a lightly populated area some 30 miles to the southeast of the city. For several hours aftershocks rocked the area.

Over the border in the U.S. town of Calexico, eight downtown blocks were closed off as Border Patrol agents helped police secure the area against looters. Stores had leaning awnings, smashed windows and broken vases in window displays.  "It was violent, like the earth was mad ... My home was shaking very violently, pictures coming off the walls, then the TVs came down," said local firefighter Channing Dawson.  Earthquakes of 7.0 can do serious damage to urban areas.  Some parts of San Diego reported minor structural damage and callers to local radio said the rolling tremor made it hard to keep cars on the road. In Los Angeles, buildings swayed.

Southern California with its myriad geological faults is prone to frequent quakes and many residents fear the next big one. The last to cause major damage was the 6.7 magnitude Northridge quake in 1994 that left 57 dead and 9,000 injured.

Damage reports from the U.S.-Mexico border region are growing after a magnitude-7.2 earthquake in Baja California that was felt from Tijuana and Los Angeles to Las Vegas and Phoenix.  The quake struck south of Mexicali, Mexico, at 3:40 p.m. Sunday, but damage also was being reported north of the border.  Calexico Fire Chief Peter Mercado tells KABC-TV in Los Angeles that there is substantial damage in the older section of the southeastern California city. Mercado says there is structural damage and broken windows, leaking gas lines and damage to the water system. But he says no injuries have been reported.

Across the border, a parking structure at the Mexicali city hall has collapsed. Mexicali is a bustling commerce center where trucks carrying goods cross into California.  A powerful earthquake in Baja California rocked the U.S.-Mexico border region Sunday, collapsing a parking structure south of the border and causing power outages in both countries as it sent out seismic waves felt from Los Angeles to Las Vegas and Arizona.

The 7.2-magnitude quake struck at 3:40 p.m. about 19 miles southeast of Mexicali, a bustling commerce center on the Mexican side of the border where trucks carrying goods cross into California. More than 900,000 people live in the greater Mexicali area.  It was the largest earthquake in the region in nearly 18 years and was followed by aftershocks or distant "triggered" earthquakes on both sides of the border, said U.S. Geological Survey seismologist Lucy Jones.

A multistory parking structure collapsed at the Mexicali city hall but no one was injured, said Baja California state Civil Protection Director Alfredo Escobedo.  Other early reports indicated only minor damage, but communication in the region more than 100 miles southeast of Los Angeles is often slow.

"I grabbed my children and said, 'Let's go outside, hurry, hurry!'" said Elizabeth Alvarez, 54, who said the quake hit as she was getting ready to leave her house with her children in an eastern Tijuana neighborhood, across the border from San Diego.  Hundreds of people fled Tijuana's beach fearing a tsunami, said Capt. Juan Manuel Hernandez, chief of aquatic rescue at the Tijuana fire department. Tsunami experts quickly reported that no tsunami was expected along the West Coast, and Hernandez said the beach filled back up with people within an hour.

Tijuana Fire Chief Rafael Carillo said firefighters were rescuing people trapped in an elevator at the Ticuan Hotel in downtown Tijuana, but mostly were responding to reports of fallen cables and minor damage to buildings.  The Crowne Plaza hotel in Mexicali had minor damage — burst pipes and broken windows — but no on was hurt, said receptionist Juan Carlos Fernandez.  "There was a little bit of panic," Fernandez said. "Wait, it's trembling again."  Guests fled their rooms at the Hotel Playa Club in San Felipe, on the Gulf of California, but there was no damage, said receptionist Araceli Marquez.

Seismologists said there have been many earthquakes in the region including many in the magnitude-3.0 range before Sunday's big shock.  "The last time we had an earthquake this large in either Baja or California was in 1992 with the Landers Earthquake, which was 7.3," Jones said.

The USGS reported three strong aftershocks within the hour, including a magnitude-5.1 jolt in the Imperial County desert east of San Diego. Magnitude-4.5 and magnitude-4.3 aftershocks were also reported. Another occurred off Malibu.

The 7.2-magnitude quake was felt as far north as Santa Barbara, USGS seismologist Susan Potter said. It was one of the strongest to hit California in recent history. Only one has been stronger — a 7.3 quake that hit Landers, Calif., and left three dead in 1992 — and there were at least two other 7.2-magnitude quakes in the last 20 years.  Seismologists also said a number of small quakes were triggered in a geothermal area in Northern California.

More than 5,000 Southern California Edison customers were affected, mostly with about 30 seconds of flickering lights. Several hundred had longer outages.  In Arizona, 3,369 customers in the Yuma area had a "relatively momentary outage" from the quake, Arizona Public Service Company spokesman Don Wool said.  Only about 70 people were still without service in the rural Gadsden and Summerton areas. But Wool said he expected electricity to be restored there in about two hours.

Clint Norred, a spokesman for the Yuma, Ariz., Police Department, said the quake was very strong there but he'd heard no reports of injuries or major damage.  In the Phoenix area, Jacqueline Land said her king-sized bed in her second-floor apartment felt like a boat gently swaying on the ocean.  "I thought to myself, 'That can't be an earthquake. I'm in Arizona,'" the Northern California native said.